CVE-2026-40253

MEDIUMNVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.8 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 94% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

openCryptoki is a PKCS#11 library and provides tooling for Linux and AIX. In versions 3.26.0 and below, the BER/DER decoding functions in the shared common library (asn1.c) accept a raw pointer but no buffer length parameter, and trust attacker-controlled BER length fields without validating them against actual buffer boundaries. All primitive decoders are affected: ber_decode_INTEGER, ber_decode_SEQUENCE, ber_decode_OCTET_STRING, ber_decode_BIT_STRING, and ber_decode_CHOICE. Additionally, ber_decode_INTEGER can produce integer underflows when the encoded length is zero. An attacker supplying a malformed BER-encoded cryptographic object through PKCS#11 operations such as C_CreateObject or C_UnwrapKey, token loading from disk, or remote backend communication can trigger out-of-bounds reads. This affects all token backends (Soft, ICA, CCA, TPM, EP11, ICSF) since the vulnerable code is in the shared common library. A patch is available thorugh commit ed378f463ef73364c89feb0fc923f4dc867332a3.

CVSS v3
6.8
EG Score
6.8(medium)
EG Risk
47(Track)
EG Risk 47/100SSVC: Track

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
Severity68% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

April 16, 2026

Last Modified

April 22, 2026

Advisory Details (2)

Auto-updated Jun 14, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

Memory safety vulnerabilities in BER/DER decoders in asn1.c · Advisory · opencryptoki/opencryptoki · GitHub

https://github.com/opencryptoki/opencryptoki/security/advisories/GHSA-c9cf-6vr4-wfxm
github_commit Patch Available

commit ed378f463ef7 (opencryptoki/opencryptoki)

Patch available: opencryptoki/opencryptoki v3.27.0 (contains commit ed378f463ef7)

https://github.com/opencryptoki/opencryptoki/commit/ed378f463ef73364c89feb0fc923f4dc867332a3

Vendor Advisories for CVE-2026-40253(6)

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

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatopencryptoki-0:3.24.0-5.el9_6.22026-07-08redhat
redhatopencryptoki-0:3.24.0-6.el10_0.22026-07-08redhat
redhatopencryptoki-0:3.22.0-3.el9_4.32026-06-30redhat
redhatopencryptoki-0:3.26.0-2.el9_8.22026-06-23redhat
redhatopencryptoki-0:3.26.0-3.el10_2.12026-06-23redhat
redhatopencryptoki-0:3.22.0-3.el8_10.32026-06-16redhat

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 rangeFixed inDependents
opencryptoki3.23.0+dfsg-0.1 ... 3.8.1+dfsg-3.2 (6 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
opencryptoki3.23.0+dfsg-0.1 ... 3.8.1+dfsg-3.2 (6 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
opencryptoki3.23.0+dfsg-0.3, 3.23.0+dfsg-0.4, 3.27.0-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
opencryptoki3.23.0+dfsg-0.3, 3.23.0+dfsg-0.43.27.0-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 25× 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 158 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-40253?
CVE-2026-40253 is a medium vulnerability published on April 16, 2026. openCryptoki is a PKCS#11 library and provides tooling for Linux and AIX. In versions 3.26.0 and below, the BER/DER decoding functions in the shared common library (asn1.c) accept a raw pointer but no buffer length parameter, and trust attacker-controlled BER length fields without validating them…
When was CVE-2026-40253 disclosed?
CVE-2026-40253 was first published in the National Vulnerability Database on April 16, 2026, with the most recent update on April 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40253 actively exploited?
CVE-2026-40253 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 94.4% of all scored CVEs.
What is the CVSS score of CVE-2026-40253?
CVE-2026-40253 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2026-40253?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40253, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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