CVE-2026-5477

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-04-10. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

An integer overflow existed in the wolfCrypt CMAC implementation, that could be exploited to forge CMAC tags. The function wc_CmacUpdate used the guard if (cmac->totalSz != 0) to skip XOR-chaining on the first block (where digest is all-zeros and the XOR is a no-op). However, totalSz is word32 and wraps to zero after 2^28 block flushes (4 GiB), causing the guard to erroneously discard the live CBC-MAC chain state. Any two messages sharing a common suffix beyond the 4 GiB mark then produce identical CMAC tags, enabling a zero-work prefix-substitution forgery. The fix removes the guard, making the XOR unconditional; the no-op property on the first block is preserved because digest is zero-initialized by wc_InitCmac_ex.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

April 10, 2026

Last Modified

April 27, 2026

Advisory Details (1)

Auto-updated Jun 15, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr.
github_pr

Various fixes

Fix merged in wolfSSL/wolfssl PR #10102 on 2026-04-06 — awaiting tagged release

https://github.com/wolfSSL/wolfssl/pull/10102

Vendor Advisories for CVE-2026-5477(1)

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 5× 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 181 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-5477?
CVE-2026-5477 is a high vulnerability published on April 10, 2026. An integer overflow existed in the wolfCrypt CMAC implementation, that could be exploited to forge CMAC tags. The function wcCmacUpdate used the guard if (cmac->totalSz != 0) to skip XOR-chaining on the first block (where digest is all-zeros and the XOR is a no-op). However, totalSz is word32 and…
When was CVE-2026-5477 disclosed?
CVE-2026-5477 was first published in the National Vulnerability Database on April 10, 2026, with the most recent update on April 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-5477 actively exploited?
CVE-2026-5477 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 64.6% of all scored CVEs.
What is the CVSS score of CVE-2026-5477?
CVE-2026-5477 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-5477?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-5477, 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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