CVE-2026-18938

MEDIUMPre-NVD 6.26.2—
EchelonGraph scoreMEDIUM confidence

Score 6.2 from GitHub Security Advisory published 2026-08-07. A secondary CVSS source baseline 6.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
6.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 6.2Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel, could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can cause the system to miscalculate memory allocation for nested attributes. This leads to a memory corruption issue, specifically a heap out-of-bounds write, which can crash the p11-kit RPC parsing process, resulting in a Denial of Service (DoS). This vulnerability is only exploitable on 32 bit systems.

CVSS v3
6.2
EG Score
6.2MEDIUMmedium confidence
EG Risk
28
EG Risk 28/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity62% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
3rd
KEV
Not listed

CISA SSVCTrack 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). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 7, 2026

Last Modified

August 14, 2026

Advisory Details (2)

Auto-updated Aug 7, 2026
Patch available. Sources: redhat.
redhat

2478995 – (CVE-2026-18938) CVE-2026-18938 p11-kit: Integer overflow in RPC attribute-array length calculation can under-allocate nested attribute storage on 32 bit systems

https://bugzilla.redhat.com/show_bug.cgi?id=2478995
redhat Patch Available

CVE-2026-18938 - 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-2026-18938

Vendor Advisories for CVE-2026-18938(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntup11-kit-modules (0.25.3-4ubuntu2.2) @ noble2026-10-05ubuntu

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
p11-kit0.23.22-1 ... 0.26.4-1 (33 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
p11-kit0.24.1-2 ... 0.26.5-1 (25 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
p11-kit0.25.10-1 ... 0.26.5-1 (9 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
p11-kit0.25.10-1 ... 0.26.4-1 (8 versions)
  • every version up to 0.26.5-1: fixed in 0.26.5-1
—

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 20× in last 7d / 86× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 171 total refreshes for this CVE.

  1. 2026-10-05 08:17 UTCEG score recompute
  2. 2026-10-05 08:17 UTCVendor advisory
  3. 2026-10-05 08:17 UTCGHSA enrichment
  4. 2026-10-04 23:21 UTCEPSS rescore
  5. 2026-10-04 05:45 UTCEG score recompute
  6. 2026-10-04 05:45 UTCVendor advisory
  7. 2026-10-04 05:45 UTCGHSA enrichment
  8. 2026-10-02 09:34 UTCEG score recompute
  9. 2026-10-02 09:34 UTCVendor advisory
  10. 2026-10-02 09:34 UTCGHSA enrichment
  11. 2026-10-01 19:49 UTCEPSS rescore
  12. 2026-09-30 22:57 UTCEG score recompute
  13. 2026-09-30 22:57 UTCVendor advisory
  14. 2026-09-30 22:56 UTCGHSA enrichment
  15. 2026-09-30 15:02 UTCEPSS rescore
  16. 2026-09-29 15:20 UTCEPSS rescore
  17. 2026-09-29 05:48 UTCEG score recompute
  18. 2026-09-29 05:48 UTCVendor advisory
  19. 2026-09-29 05:48 UTCGHSA enrichment
  20. 2026-09-28 13:51 UTCEPSS rescore
  21. 2026-09-27 17:11 UTCEG score recompute
  22. 2026-09-27 17:11 UTCVendor advisory
  23. 2026-09-27 17:11 UTCGHSA enrichment
  24. 2026-09-27 13:47 UTCEPSS rescore
  25. 2026-09-26 15:58 UTCEPSS rescore
Show 75 more
  1. 2026-09-25 07:12 UTCEG score recompute
  2. 2026-09-25 07:12 UTCVendor advisory
  3. 2026-09-25 07:12 UTCGHSA enrichment
  4. 2026-09-24 05:04 UTCEG score recompute
  5. 2026-09-24 05:04 UTCVendor advisory
  6. 2026-09-24 05:04 UTCGHSA enrichment
  7. 2026-09-23 02:55 UTCEG score recompute
  8. 2026-09-23 02:55 UTCVendor advisory
  9. 2026-09-23 02:55 UTCGHSA enrichment
  10. 2026-09-22 00:47 UTCEG score recompute
  11. 2026-09-22 00:47 UTCVendor advisory
  12. 2026-09-22 00:47 UTCGHSA enrichment
  13. 2026-09-20 20:33 UTCEG score recompute
  14. 2026-09-20 20:33 UTCVendor advisory
  15. 2026-09-20 20:33 UTCGHSA enrichment
  16. 2026-09-19 12:58 UTCEG score recompute
  17. 2026-09-19 12:58 UTCVendor advisory
  18. 2026-09-19 12:58 UTCGHSA enrichment
  19. 2026-09-18 19:27 UTCEPSS rescore
  20. 2026-09-18 07:25 UTCEG score recompute
  21. 2026-09-18 07:25 UTCVendor advisory
  22. 2026-09-18 07:25 UTCGHSA enrichment
  23. 2026-09-17 05:17 UTCEG score recompute
  24. 2026-09-17 05:17 UTCVendor advisory
  25. 2026-09-17 05:17 UTCGHSA enrichment
  26. 2026-09-16 14:07 UTCEPSS rescore
  27. 2026-09-16 03:09 UTCEG score recompute
  28. 2026-09-16 03:09 UTCVendor advisory
  29. 2026-09-16 03:09 UTCGHSA enrichment
  30. 2026-09-15 01:01 UTCVendor advisory
  31. 2026-09-15 01:01 UTCGHSA enrichment
  32. 2026-09-13 18:43 UTCEG score recompute
  33. 2026-09-13 18:43 UTCVendor advisory
  34. 2026-09-13 18:43 UTCGHSA enrichment
  35. 2026-09-13 16:46 UTCEPSS rescore
  36. 2026-09-12 16:35 UTCEG score recompute
  37. 2026-09-12 16:35 UTCVendor advisory
  38. 2026-09-12 16:35 UTCGHSA enrichment
  39. 2026-09-12 15:00 UTCEPSS rescore
  40. 2026-09-11 14:52 UTCEPSS rescore
  41. 2026-09-11 14:27 UTCEG score recompute
  42. 2026-09-11 14:27 UTCVendor advisory
  43. 2026-09-11 14:27 UTCGHSA enrichment
  44. 2026-09-11 09:36 UTCEPSS rescore
  45. 2026-09-10 09:34 UTCEPSS rescore
  46. 2026-09-10 08:09 UTCVendor advisory
  47. 2026-09-10 08:09 UTCGHSA enrichment
  48. 2026-09-09 06:01 UTCEG score recompute
  49. 2026-09-09 06:01 UTCVendor advisory
  50. 2026-09-09 06:01 UTCGHSA enrichment
  51. 2026-09-08 22:00 UTCEPSS rescore
  52. 2026-09-07 17:46 UTCEG score recompute
  53. 2026-09-07 17:46 UTCVendor advisory
  54. 2026-09-07 17:46 UTCGHSA enrichment
  55. 2026-09-06 13:47 UTCEPSS rescore
  56. 2026-09-06 13:23 UTCEG score recompute
  57. 2026-09-06 13:23 UTCVendor advisory
  58. 2026-09-06 13:23 UTCGHSA enrichment
  59. 2026-09-05 11:15 UTCEG score recompute
  60. 2026-09-05 11:15 UTCVendor advisory
  61. 2026-09-05 11:15 UTCGHSA enrichment
  62. 2026-09-04 09:07 UTCEG score recompute
  63. 2026-09-04 09:07 UTCVendor advisory
  64. 2026-09-04 09:07 UTCGHSA enrichment
  65. 2026-09-04 05:06 UTCEPSS rescore
  66. 2026-09-03 06:08 UTCEG score recompute
  67. 2026-09-03 06:08 UTCVendor advisory
  68. 2026-09-03 06:08 UTCGHSA enrichment
  69. 2026-09-02 14:11 UTCEPSS rescore
  70. 2026-09-02 00:48 UTCEG score recompute
  71. 2026-09-02 00:48 UTCVendor advisory
  72. 2026-09-02 00:47 UTCGHSA enrichment
  73. 2026-09-01 13:53 UTCEPSS rescore
  74. 2026-08-31 22:30 UTCEG score recompute
  75. 2026-08-31 22:30 UTCVendor advisory

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ubuntu:USN-8687-1

Frequently asked(5)

What is CVE-2026-18938?
CVE-2026-18938 is a medium vulnerability published on August 7, 2026. A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel, could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can cause the system to miscalculate memory allocation for nested attributes. This leads to a…
When was CVE-2026-18938 disclosed?
CVE-2026-18938 was first published on August 7, 2026, with the most recent update on August 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18938 actively exploited?
CVE-2026-18938 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (3rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18938?
CVE-2026-18938 has a CVSS base score of 6.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-18938?
A fix for CVE-2026-18938 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-18938 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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