CVE-2026-3549

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: HIGH) published 2026-03-19. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

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

Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
41%
KEV
Not listed

Published

March 19, 2026

Last Modified

June 17, 2026

Advisory Details (1)

Auto-updated Sep 14, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr.
github_pr

Static code analysis fixes

Fix merged in wolfSSL/wolfssl PR #9817 on 2026-02-26 — awaiting tagged release

https://github.com/wolfSSL/wolfssl/pull/9817

Vendor Advisories for CVE-2026-3549(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 7× in last 7d / 27× 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.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-3549?
CVE-2026-3549 is a critical vulnerability published on March 19, 2026. Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.
When was CVE-2026-3549 disclosed?
CVE-2026-3549 was first published in the National Vulnerability Database on March 19, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-3549 actively exploited?
CVE-2026-3549 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 59.0% of all scored CVEs.
What is the CVSS score of CVE-2026-3549?
CVE-2026-3549 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-3549?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-3549, 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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