CVE-2026-3549

8.3 highEPSS 0.5%

High (8.3) in wolfssl wolfssl. EPSS 0.5% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

8.3 high

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:L/SI:L/SA:L

CVSS 3.1

9.8 critical

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

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-31)
CWE: CWE-122
Published: 2026-03-19
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

wolfssl:wolfssl

References

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

Check your stack JSON