CVE-2026-6291

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2026-06-25. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Bleichenbacher padding oracle in PKCS#7 KTRI decryption. When decrypting PKCS#7 EnvelopedData using RSA PKCS#1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to submit crafted EnvelopedData messages and observe error responses could use this as a padding oracle to incrementally recover the encrypted Content Encryption Key (CEK). The fix generates a deterministic pseudo-random fake CEK on padding failure (via HMAC-SHA256) and proceeds with decryption identically, using constant-time operations throughout, so that all failure paths produce the same error regardless of padding validity.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

June 25, 2026

Last Modified

June 26, 2026

Advisory Details (2)

Auto-updated Jun 25, 2026
Patch available. Sources: github_pr.
generic Patch Available

wolfSSL Security Vulnerabilities | Documentation - wolfSSL

https://www.wolfssl.com/docs/security-vulnerabilities/
github_pr

PKCS#7 fixes

Fix merged in wolfSSL/wolfssl PR #10203 on 2026-04-24 — awaiting tagged release

https://github.com/wolfSSL/wolfssl/pull/10203

Vendor Advisories for CVE-2026-6291(2)

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

Affected Packages

(3 across 3 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
wolfssl4.6.0+p1-0+deb11u1 ... 5.9.2-1 (40 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
wolfssl5.5.4-2 ... 5.9.2-1 (27 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
wolfssl5.7.2-0.1 ... 5.9.2-1 (14 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 40× 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 189 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-6291?
CVE-2026-6291 is a medium vulnerability published on June 25, 2026. Bleichenbacher padding oracle in PKCS#7 KTRI decryption. When decrypting PKCS#7 EnvelopedData using RSA PKCS#1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to…
When was CVE-2026-6291 disclosed?
CVE-2026-6291 was first published in the National Vulnerability Database on June 25, 2026, with the most recent update on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-6291 actively exploited?
CVE-2026-6291 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 84.1% of all scored CVEs.
What is the CVSS score of CVE-2026-6291?
CVE-2026-6291 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-6291?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6291, 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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