CVE-2026-18917

HIGHPre-NVD 7.87.8
EchelonGraph scoreMEDIUM confidence

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

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-20. A secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-63239 (ENISA EUVD) · GHSA-6jq9-9f7w-h7mc (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in libvirt. An unprivileged local user could exploit an integer overflow vulnerability in the NodeGetFreePages RPC handler. This flaw allows crafted values to bypass a size check, leading to an undersized memory buffer. Subsequently, real NUMA node data can overwrite this buffer. This heap buffer overflow can corrupt the root libvirt daemon's memory, potentially leading to a denial of service or local privilege escalation.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

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)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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.
EPSS PROB
0.2%
EPSS %ILE
7th
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 (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade 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; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (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

August 20, 2026

Last Modified

October 27, 2026

Advisory Details (2)

Auto-updated Aug 20, 2026
Patch available. Sources: redhat.
Red Hat

2520161 – (CVE-2026-18917) CVE-2026-18917 libvirt: Integer overflow in NodeGetFreePages RPC handler leading to heap buffer overflow

https://bugzilla.redhat.com/show_bug.cgi?id=2520161
Red HatMentions a patch (unverified)

CVE-2026-18917 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-18917

Patch Availability(12)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibvirt0 (8.0.0-1ubuntu7.21) @ jammy2026-10-27ubuntu
ubuntulibvirt0-hwe (12.0.0-1ubuntu5.5) @ resolute2026-10-27ubuntu
redhatlibvirt-0:11.10.0-12.9.el10_22026-10-05redhat
redhatlibvirt-0:11.10.0-12.7.el9_82026-10-02redhat
redhatvirt:rhel-8040020260916092751.522a0ee42026-09-21redhat
redhatlibvirt-0:4.5.0-36.el7_9.72026-09-21redhat
redhatlibvirt-0:9.0.0-10.17.el9_22026-09-17redhat
redhatlibvirt-0:10.0.0-6.24.el9_42026-09-17redhat
redhatvirt:rhel-8060020260910092451.ad008a3a2026-09-17redhat
redhatlibvirt-0:10.10.0-7.19.el9_62026-09-17redhat
redhatlibvirt-0:10.10.0-8.12.el10_02026-09-17redhat
redhatvirt:rhel-8080020260910092120.63b345852026-09-17redhat

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
libvirt10.0.0-1 ... 9.9.0-1 (72 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
libvirt11.3.0-3, 11.3.0-3+deb13u1, 11.3.0-3+deb13u2
  • every version up to 11.3.0-3+deb13u3: fixed in 11.3.0-3+deb13u3
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
libvirt11.10.0-1 ... 12.6.0-1 (18 versions)
  • every version up to 12.7.0-1: fixed in 12.7.0-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(2)

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 10× in last 7d / 68× 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 98 of 284 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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 186 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 0.2% · 7th percentile
  2. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  3. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  4. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  5. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  6. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  7. 2026-10-27 10:26 UTCEG score recompute
  8. 2026-10-27 10:26 UTCVendor advisory
  9. 2026-10-27 10:26 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  11. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  12. 2026-10-25 14:44 UTCEG score recompute
  13. 2026-10-24 17:48 UTCEG score recompute
  14. 2026-10-24 17:48 UTCVendor advisory
  15. 2026-10-24 17:48 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  17. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  18. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  19. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  20. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  21. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  22. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  23. 2026-10-18 03:58 UTCEG score recompute
  24. 2026-10-17 17:47 UTCEG score recompute
  25. 2026-10-17 17:47 UTCVendor advisory
Show 73 more
  1. 2026-10-17 17:46 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  2. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  3. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  4. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  5. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  6. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  7. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  8. 2026-10-12 16:26 UTCEG score recompute
  9. 2026-10-11 20:07 UTCEG score recompute
  10. 2026-10-11 17:19 UTCEG score recompute
  11. 2026-10-11 14:52 UTCEG score recompute
  12. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  13. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  14. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  15. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  16. 2026-10-08 05:40 UTCEG score recompute
  17. 2026-10-08 05:40 UTCVendor advisory
  18. 2026-10-08 05:40 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  19. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  20. 2026-10-07 05:46 UTCVendor advisory
  21. 2026-10-07 05:46 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  22. 2026-10-06 16:56 UTCEG score recompute
  23. 2026-10-06 16:56 UTCVendor advisory
  24. 2026-10-06 16:56 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  25. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  26. 2026-10-06 03:39 UTCEG score recompute
  27. 2026-10-06 03:39 UTCVendor advisory
  28. 2026-10-06 03:39 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  29. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  30. 2026-10-05 09:25 UTCEG score recompute
  31. 2026-10-05 09:25 UTCVendor advisory
  32. 2026-10-05 09:25 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  33. 2026-10-05 08:58 UTCEG score recompute
  34. 2026-10-05 08:58 UTCVendor advisory
  35. 2026-10-05 08:58 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  36. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  37. 2026-10-04 21:43 UTCVendor advisory
  38. 2026-10-04 21:43 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  39. 2026-10-04 08:54 UTCVendor advisory
  40. 2026-10-04 08:54 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  41. 2026-10-03 20:04 UTCEG score recompute
  42. 2026-10-03 20:04 UTCVendor advisory
  43. 2026-10-03 20:04 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  44. 2026-10-03 07:12 UTCVendor advisory
  45. 2026-10-03 07:12 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  46. 2026-10-02 18:22 UTCEG score recompute
  47. 2026-10-02 18:22 UTCVendor advisory
  48. 2026-10-02 18:22 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  49. 2026-10-02 05:22 UTCEG score recompute
  50. 2026-10-02 05:22 UTCVendor advisory
  51. 2026-10-02 05:22 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  52. 2026-10-02 04:42 UTCEG score recompute
  53. 2026-10-02 04:42 UTCVendor advisory
  54. 2026-10-02 04:41 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  55. 2026-10-01 22:57 UTCEG score recompute
  56. 2026-10-01 22:57 UTCVendor advisory
  57. 2026-10-01 22:57 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  58. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  59. 2026-10-01 10:08 UTCVendor advisory
  60. 2026-10-01 10:08 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  61. 2026-09-30 21:18 UTCEG score recompute
  62. 2026-09-30 21:18 UTCVendor advisory
  63. 2026-09-30 21:18 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  64. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  65. 2026-09-30 08:25 UTCEG score recompute
  66. 2026-09-30 08:25 UTCVendor advisory
  67. 2026-09-30 08:25 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  69. 2026-09-28 21:40 UTCEG score recompute
  70. 2026-09-28 21:40 UTCVendor advisory
  71. 2026-09-28 21:40 UTCGHSA enrichmentGHSA-6jq9-9f7w-h7mc · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  73. 2026-09-28 05:07 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-18917?
CVE-2026-18917 is a high-severity vulnerability; its CVE record was published on August 20, 2026. A flaw was found in libvirt. An unprivileged local user could exploit an integer overflow vulnerability in the NodeGetFreePages RPC handler. This flaw allows crafted values to bypass a size check, leading to an undersized memory buffer. Subsequently, real NUMA node data can overwrite this buffer.…
When was CVE-2026-18917 made public?
CVE-2026-18917 was made public on August 12, 2025: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on August 20, 2026. EchelonGraph's copy of the record carries a last-modified date of October 27, 2026; the record at its source may have been updated since.
Is CVE-2026-18917 actively exploited?
CVE-2026-18917 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18917?
CVE-2026-18917 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-18917?
A fix for CVE-2026-18917 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-18917 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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