CVE catalog

CVE-2026-3549

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.

[CVE catalog]

Severity: High · CVSS 8.3
Published: Mar 19, 2026, 9:17:12 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.50% · Oct 25, 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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	wolfssl	sid	`5.9.2-1.2`	fixed
Debian	wolfssl	trixie	`5.7.2-0.1+deb13u2`	vulnerable
Debian	wolfssl	bookworm	`5.5.4-2+deb12u2`	vulnerable
Debian	wolfssl	bookworm-security	`5.5.4-2+deb12u3`	vulnerable
Cpe	wolfssl	Not reported	Not reported	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	wolfssl	source	sid	`5.9.0-0.1`	not yet assigned	Not reported	Not reported
Debian	wolfssl	source	trixie	`(unfixed)`	not yet assigned	Not reported	Not reported
Debian	wolfssl	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported

Notes

[trixie] wolfssl: Minor issue [bookworm] wolfssl: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libwolfssl35]Affected
Source package: [wolfssl]
Details (4)
- 5.5.4-2+deb12u2 · amd64 · bookworm
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u2 · arm64 · bookworm
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · amd64 · bookworm-security
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · arm64 · bookworm-security
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
[libwolfssl-dev]Affected
Source package: [wolfssl]
Details (4)
- 5.5.4-2+deb12u2 · amd64 · bookworm
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u2 · arm64 · bookworm
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · amd64 · bookworm-security
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · arm64 · bookworm-security
  Affected
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12

[Debian 13 (Trixie)]

[libwolfssl42t64]Affected
Source package: [wolfssl]
Details (2)
- 5.7.2-0.1+deb13u1 · amd64 · trixie
  Affected
  nvd · wolfssl · debian · 13
- 5.7.2-0.1+deb13u1 · arm64 · trixie
  Affected
  nvd · wolfssl · debian · 13
[libwolfssl-dev]Affected
Source package: [wolfssl]
Details (2)
- 5.7.2-0.1+deb13u1 · amd64 · trixie
  Affected
  nvd · wolfssl · debian · 13
- 5.7.2-0.1+deb13u1 · arm64 · trixie
  Affected
  nvd · wolfssl · debian · 13

Observed: Oct 23, 2026, 10:40:19 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database]