CVE-2023-42755

MEDIUMNVD 5.56.5
EchelonGraph scoreMEDIUM confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score 6.5 from GitHub Security Advisory published 2023-10-05. NVD baseline CVSS 5.5; sources differ by 1.0.

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

Also known asEUVD-2023-47187 (ENISA EUVD) · GHSA-qhrq-6m4q-9x2x (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in the IPv4 Resource Reservation Protocol (RSVP) classifier in the Linux kernel. The xprt pointer may go beyond the linear part of the skb, leading to an out-of-bounds read in the rsvp_classify function. This issue may allow a local user to crash the system and cause a denial of service.

CVSS v3
5.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

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)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 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 every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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.
EPSS PROB
0.4%
EPSS %ILE
35th
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 (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). 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 every mission impact level.CISA BOD 26-04: 60 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 every mission impact level.

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

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 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 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

October 5, 2023

Last Modified

October 15, 2026

Advisory Details (9)

Auto-updated Oct 15, 2026
🔬 Proof of concept available. Patch available. Sources: redhat.
Web pageMentions a patch (unverified)

SSA-398330

https://cert-portal.siemens.com/productcert/html/ssa-398330.html
Web pageMentions a patch (unverified)

[SECURITY] [DLA 3710-1] linux security update

https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
Web pageMentions a patch (unverified)

[SECURITY] [DLA 3623-1] linux-5.10 security update

https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
Web page🟡 PoC Available

oss-sec: [CVE-2023-42755] Linux kernel wild pointer access <= v6.2

https://seclists.org/oss-sec/2023/q3/229
Red HatMentions a patch (unverified)

2239847 – (CVE-2023-42755, ZDI-CAN-18387) CVE-2023-42755 kernel: rsvp: out-of-bounds read in rsvp_classify()

Affected: Red Hat Enterprise Linux 8

https://bugzilla.redhat.com/show_bug.cgi?id=2239847
Red HatMentions a patch (unverified)

CVE-2023-42755 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 9 is not affected by this CVE.

https://access.redhat.com/security/cve/CVE-2023-42755
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2024:3138
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2024:2950

Patch Availability(21)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-starfive (6.2.0.1007.8~22.04.1) @ jammy2026-10-15ubuntu
ubuntulinux-tools-aws-hwe (4.15.0.1162.145) @ xenial2026-10-15ubuntu
ubuntulinux-tools-aws (4.4.0.1124.121) @ trusty2026-10-15ubuntu
ubuntulinux-tools-azure (4.15.0.1171.137) @ trusty2026-10-15ubuntu
ubuntulinux-tools-intel-iotg (5.15.0.1043.43) @ jammy2026-10-15ubuntu
ubuntulinux-tools-gkeop-edge (5.15.0.1031.37~20.04.27) @ focal2026-10-15ubuntu
ubuntulinux-tools-oracle-edge (5.15.0.1046.52~20.04.1) @ focal2026-10-15ubuntu
ubuntulinux-tools-raspi2-hwe-18.04-edge (5.4.0.1096.126) @ focal2026-10-15ubuntu
ubuntulinux-virtual-hwe-16.04-edge (4.15.0.219.3) @ xenial2026-10-15ubuntu
ubuntulinux-virtual (3.13.0.194.204) @ trusty2026-10-15ubuntu
ubuntulinux-tools-nvidia-hwe-22.04-edge (6.2.0.1011.13) @ jammy2026-10-15ubuntu
ubuntulinux-tools-intel-iotg-edge (5.15.0.1043.49~20.04.33) @ focal2026-10-15ubuntu
ubuntulinux-tools-oem-22.04c (6.1.0.1024.25) @ jammy2026-10-15ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.2.0.35.35) @ lunar2026-10-15ubuntu
ubuntulinux-virtual-lts-xenial (4.4.0.246.252) @ xenial2026-10-15ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.4.0-1032 (5.4.0-1032.36) @ focal2026-10-15ubuntu
ubuntulinux-tools-bluefield (5.4.0.1073.68) @ focal2026-10-15ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.87.84) @ jammy2026-10-15ubuntu
ubuntulinux-tools-gcp-edge (5.4.0.1116.92) @ bionic2026-10-15ubuntu
redhatkernel-0:4.18.0-553.el8_102024-05-22redhat
redhatkernel-rt-0:4.18.0-553.rt7.342.el8_102024-05-22redhat

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

(6 across 5 ecosystems)
Debian:10(2)
PackageVulnerable rangeFix by version rangeDependents
linux4.19.118-1 ... 4.19.98-1~bpo9+1 (45 versions)
  • every version up to 4.19.304-1: fixed in 4.19.304-1
—
linux-5.105.10.136-1~deb10u1 ... 5.10.179-5~deb10u1 (10 versions)
  • every version up to 5.10.197-1~deb10u1: fixed in 5.10.197-1~deb10u1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (34 versions)
  • every version up to 5.10.197-1: fixed in 5.10.197-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.27-1 ... 6.1.55-1~bpo11+1 (10 versions)
  • every version up to 6.1.55-1: fixed in 6.1.55-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 6.3.7-1: fixed in 6.3.7-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 6.3.7-1: fixed in 6.3.7-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(19)

Data Freshness Timeline

(refreshed 8× in last 7d / 41× 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 90 of 221 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. 10 repeat rows among the latest 100 are merged into the row they repeat. The 131 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:40 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  2. 2026-11-01 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  3. 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  4. 2026-10-30 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  5. 2026-10-29 16:30 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  6. 2026-10-28 16:29 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  7. 2026-10-27 16:29 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  8. 2026-10-27 15:55 UTCOSV refresh
  9. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  10. 2026-10-25 17:35 UTCEG score recompute
  11. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  12. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  13. 2026-10-23 16:29 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  14. 2026-10-22 16:31 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  15. 2026-10-21 16:29 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  16. 2026-10-20 16:30 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  17. 2026-10-19 16:29 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  18. 2026-10-18 16:29 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  19. 2026-10-18 07:51 UTCEG score recompute
  20. 2026-10-17 16:30 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  21. 2026-10-16 16:36 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  22. 2026-10-15 16:29 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  23. 2026-10-15 00:29 UTCVendor advisory
  24. 2026-10-15 00:28 UTCGHSA enrichmentGHSA-qhrq-6m4q-9x2x · GitHub CVSS 6.5
  25. 2026-10-15 00:03 UTCEG score recompute
Show 65 more
  1. 2026-10-15 00:03 UTCVendor advisory
  2. 2026-10-15 00:02 UTCGHSA enrichmentGHSA-qhrq-6m4q-9x2x · GitHub CVSS 6.5
  3. 2026-10-14 16:30 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  4. 2026-10-13 16:30 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  5. 2026-10-12 23:24 UTCOSV refresh
  6. 2026-10-12 18:19 UTCEG score recompute
  7. 2026-10-12 16:31 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  8. 2026-10-11 21:45 UTCEG score recompute
  9. 2026-10-11 13:45 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  10. 2026-10-10 19:57 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  11. 2026-10-09 20:05 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  12. 2026-10-08 17:06 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  13. 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  14. 2026-10-06 15:15 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  15. 2026-10-05 17:41 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  16. 2026-10-04 23:20 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  17. 2026-10-03 14:23 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  18. 2026-10-01 19:48 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  19. 2026-09-30 16:30 UTCEG score recompute
  20. 2026-09-30 15:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  21. 2026-09-29 15:17 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  22. 2026-09-28 13:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  23. 2026-09-27 13:42 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  24. 2026-09-26 15:56 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  25. 2026-09-26 00:22 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  26. 2026-09-24 14:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  27. 2026-09-23 13:46 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  28. 2026-09-22 21:31 UTCOSV refresh
  29. 2026-09-20 20:14 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  30. 2026-09-18 19:25 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  31. 2026-09-17 19:25 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  32. 2026-09-16 14:06 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  33. 2026-09-16 05:11 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  34. 2026-09-13 16:44 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  35. 2026-09-12 14:58 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  36. 2026-09-11 14:50 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  37. 2026-09-11 09:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  38. 2026-09-08 21:58 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  39. 2026-09-07 15:59 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  40. 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  41. 2026-09-05 15:26 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  42. 2026-09-04 13:58 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  43. 2026-09-04 05:04 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  44. 2026-09-03 16:46 UTCOSV refresh
  45. 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  46. 2026-09-01 13:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  47. 2026-08-30 19:15 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  48. 2026-08-30 01:20 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  49. 2026-08-28 21:39 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  50. 2026-08-27 14:23 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  51. 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  52. 2026-08-25 13:46 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  53. 2026-08-23 00:17 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  54. 2026-08-21 23:47 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  55. 2026-08-20 22:53 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  56. 2026-08-19 17:02 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  57. 2026-08-18 13:46 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  58. 2026-08-17 13:45 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  59. 2026-08-17 05:57 UTCOSV refresh
  60. 2026-08-16 14:54 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  61. 2026-08-16 02:12 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  62. 2026-08-15 01:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  63. 2026-08-13 21:58 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  64. 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  65. 2026-08-11 13:39 UTCEPSS rescoreEPSS 0.4% · 33rd percentile

Frequently asked(5)

What is CVE-2023-42755?
CVE-2023-42755 is a medium-severity vulnerability; its CVE record was published on October 5, 2023. A flaw was found in the IPv4 Resource Reservation Protocol (RSVP) classifier in the Linux kernel. The xprt pointer may go beyond the linear part of the skb, leading to an out-of-bounds read in the rsvp_classify function. This issue may allow a local user to crash the system and cause a denial of…
When was CVE-2023-42755 made public?
CVE-2023-42755 was made public on September 25, 2023: 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 October 5, 2023. EchelonGraph's copy of the record carries a last-modified date of October 15, 2026; the record at its source may have been updated since.
Is CVE-2023-42755 actively exploited?
CVE-2023-42755 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2023-42755?
CVE-2023-42755 has a CVSS v3 base score of 5.5 (NVD). EchelonGraph synthesises NVD + FIRST EPSS + GHSA into a combined EG score of 6.5 (MEDIUM).
How do I remediate CVE-2023-42755?
A fix for CVE-2023-42755 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2023-42755 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-42755

Explore →

Is Your Infrastructure Affected by CVE-2023-42755?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.