Paper/Archive/CVE-2026-3549

CVE-2026-3549

wofSSL wolfSSL — ECH parsing heap buffer overflow

CVSS 9.8 (NVD)9.8 / 10 × 3029.4 Not in CISA KEV+300.0 EPSS percentile 42.6.426 × 208.5 No public exploit+100.0 SSVC exploitation: none+100.0

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource

wolfSSL< 5.9.05.9.0CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

wolfSSL (CNA)8.3CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:L/SI:L/SA:L

CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/wolfSSL/wolfssl/pull/9817