CVE-2026-22991

MEDIUMNVD 5.55.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 5.5 from GitHub Security Advisory published 2026-01-23. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-4291 (ENISA EUVD) · GHSA-953j-p37p-r755 (GitHub Security Advisories)Source: ENISA EUVD

5.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

libceph: make free_choose_arg_map() resilient to partial allocation

free_choose_arg_map() may dereference a NULL pointer if its caller fails after a partial allocation.

For example, in decode_choose_args(), if allocation of arg_map->args fails, execution jumps to the fail label and free_choose_arg_map() is called. Since arg_map->size is updated to a non-zero value before memory allocation, free_choose_arg_map() will iterate over arg_map->args and dereference a NULL pointer.

To prevent this potential NULL pointer dereference and make free_choose_arg_map() more resilient, add checks for pointers before iterating.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
40
EG Risk 40/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity55% × 45%
Impact severity (EG Severity): CVSS 5.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
40th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.

EG Severity
5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

January 23, 2026

Last Modified

October 19, 2026

Advisory Details (7)

Auto-updated Aug 5, 2026
Patch available.
Web page

libceph: make free_choose_arg_map() resilient to partial allocation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e3fe30e57649c551757a02e1cad073c47e1e075e
Web page

libceph: make free_choose_arg_map() resilient to partial allocation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f21c3fdb96833aac2f533506899fe38c19cf49d5
Web page

libceph: make free_choose_arg_map() resilient to partial allocation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c4c2152a858c0ce4d2bff6ca8c1d5b0ef9f2cbdf
Web page

libceph: make free_choose_arg_map() resilient to partial allocation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8081faaf089db5280c3be820948469f7c58ef8dd
Web page

libceph: make free_choose_arg_map() resilient to partial allocation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ec1850f663da64842614c86b20fe734be070c2ba
Web page

libceph: make free_choose_arg_map() resilient to partial allocation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/851241d3f78a5505224dc21c03d8692f530256b4
Web page

libceph: make free_choose_arg_map() resilient to partial allocation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9b3730dabcf3764bfe3ff07caf55e641a0b45234

Vendor Advisories for CVE-2026-22991(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(26)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-virtual-6.8 (6.8.0-117.117) @ noble2026-10-19ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1054.57.1) @ noble2026-10-19ubuntu
ubuntulinux-tools-fips-6.8 (6.8.0-116.116+fips1) @ noble2026-10-19ubuntu
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1024.24) @ noble2026-10-19ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1032.33) @ noble2026-10-19ubuntu
ubuntulinux-tools-nvidia-hwe-22.04-edge (6.8.0-1054.57~22.04.1) @ jammy2026-10-19ubuntu
ubuntulinux-tools-azure-edge (6.8.0-1059.65~22.04.1) @ jammy2026-10-19ubuntu
ubuntulinux-tools-intel-iot-realtime-5.15 (5.15.0.1094.98) @ jammy2026-10-19ubuntu
ubuntulinux-tools-raspi-nolpae (5.15.0.1097.95) @ jammy2026-10-19ubuntu
ubuntulinux-tools-azure-fips-5.15 (5.15.0.1109.94) @ jammy2026-10-19ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1056.62) @ noble2026-10-19ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1059.65+fips1) @ noble2026-10-19ubuntu
ubuntulinux-tools-realtime-hwe-24.04 (6.17.0-1018.20~24.04.1) @ noble2026-10-19ubuntu
ubuntulinux-tools-oem-6.17 (6.17.0-1030.30) @ noble2026-10-19ubuntu
ubuntulinux-tools-azure-6.17 (6.17.0-1021.21~24.04.1) @ noble2026-10-19ubuntu
ubuntulinux-tools-azure-fde-6.17 (6.17.0-1018.18~24.04.1) @ noble2026-10-19ubuntu
ubuntulinux-tools-oracle-64k-6.17 (6.17.0-1019.19~24.04.3+1) @ noble2026-10-19ubuntu
ubuntulinux-tools-nvidia-hwe-24.04 (6.17.0-1031.31) @ noble2026-10-19ubuntu
ubuntulinux-tools-realtime-5.15 (5.15.0.1102.106) @ jammy2026-10-19ubuntu
ubuntulinux-tools-azure-lts-22.04 (5.15.0.1109.107) @ jammy2026-10-19ubuntu
ubuntulinux-tools-azure-edge (5.15.0.1110.119~20.04.1) @ focal2026-10-19ubuntu
ubuntulinux-tools-nvidia-tegra-igx-rt-5.15 (5.15.0.1044.46) @ jammy2026-10-19ubuntu
ubuntulinux-tools-gcp-fips-5.15 (5.15.0.1103.93) @ jammy2026-10-19ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1055.55~20.04.1) @ focal2026-10-19ubuntu
ubuntulinux-tools-gke-5.15 (5.15.0.1099.98) @ jammy2026-10-19ubuntu
linuxKernel @ 5.10.248 (fixes >=4.13.0)—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (48 versions)
  • every version up to 5.10.249-1: fixed in 5.10.249-1
—
linux-6.16.1.106-3~deb11u1 ... 6.1.159-1~deb11u1 (14 versions)
  • every version up to 6.1.162-1~deb11u1: fixed in 6.1.162-1~deb11u1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (46 versions)
  • every version up to 6.1.162-1: fixed in 6.1.162-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.69-1~bpo12+1 (10 versions)
  • every version up to 6.12.69-1: fixed in 6.12.69-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.18~rc7-1~exp1 (97 versions)
  • every version up to 6.18.8-1: fixed in 6.18.8-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(24)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 8× in last 7d / 42× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 245 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 146 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  2. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  3. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  4. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  5. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  6. 2026-10-28 12:25 UTCOSV refresh
  7. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  8. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  9. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  10. 2026-10-25 14:42 UTCEG score recompute
  11. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  12. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  15. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  16. 2026-10-19 19:39 UTCVendor advisory
  17. 2026-10-19 19:39 UTCGHSA enrichmentGHSA-953j-p37p-r755 · GitHub CVSS 5.5
  18. 2026-10-19 18:33 UTCEG score recompute
  19. 2026-10-19 18:33 UTCVendor advisory
  20. 2026-10-19 18:33 UTCGHSA enrichmentGHSA-953j-p37p-r755 · GitHub CVSS 5.5
  21. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  23. 2026-10-18 03:55 UTCEG score recompute
  24. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  25. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.4% · 36th percentile
Show 74 more
  1. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  2. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-12 16:21 UTCEG score recompute
  6. 2026-10-11 20:03 UTCEG score recompute
  7. 2026-10-11 17:16 UTCEG score recompute
  8. 2026-10-11 14:48 UTCEG score recompute
  9. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-08 19:53 UTCOSV refresh
  13. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  14. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  15. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  16. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  17. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  18. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  19. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  20. 2026-09-29 15:21 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  21. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  22. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  24. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  25. 2026-09-24 14:03 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  26. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  27. 2026-09-19 01:30 UTCOSV refresh
  28. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  29. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  30. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  31. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  32. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  33. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  34. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  35. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  36. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  37. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  38. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  39. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  40. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  41. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  42. 2026-08-31 04:54 UTCOSV refresh
  43. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  44. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  45. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  46. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  47. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  48. 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  49. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  50. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  51. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  52. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  53. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  54. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  55. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  56. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  57. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  58. 2026-08-14 12:28 UTCEG score recompute
  59. 2026-08-14 12:28 UTCVendor advisory
  60. 2026-08-14 12:28 UTCGHSA enrichmentGHSA-953j-p37p-r755 · GitHub CVSS 5.5
  61. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  62. 2026-08-13 04:57 UTCEG score recompute
  63. 2026-08-13 04:57 UTCVendor advisory
  64. 2026-08-13 04:57 UTCGHSA enrichmentGHSA-953j-p37p-r755 · GitHub CVSS 5.5
  65. 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  66. 2026-08-11 13:42 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  67. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  68. 2026-08-09 18:27 UTCEG score recompute
  69. 2026-08-09 18:27 UTCVendor advisory
  70. 2026-08-09 18:27 UTCGHSA enrichmentGHSA-953j-p37p-r755 · GitHub CVSS 5.5
  71. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  72. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  73. 2026-08-07 23:39 UTCEG score recompute
  74. 2026-08-07 23:39 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-22991?
CVE-2026-22991 is a medium-severity vulnerability; its CVE record was published on January 23, 2026. In the Linux kernel, the following vulnerability has been resolved: libceph: make free_choose_arg_map() resilient to partial allocation free_choose_arg_map() may dereference a NULL pointer if its caller fails after a partial allocation. For example, in decode_choose_args(), if allocation of…
When was the CVE record for CVE-2026-22991 published?
The CVE record for CVE-2026-22991 was published on January 23, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 19, 2026; the record at its source may have been updated since.
Is CVE-2026-22991 actively exploited?
CVE-2026-22991 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (40th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-22991?
CVE-2026-22991 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-22991?
A fix for CVE-2026-22991 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-22991 are linked in the Vendor Advisories panel on this page.

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