CVE catalog

CVE-2026-34877

Severity: Critical · CVSS 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: Apr 2, 2026, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.43% · Oct 25, 2026

An issue was discovered in Mbed TLS versions from 2.19.0 up to 3.6.5, Mbed TLS 4.0.0. Insufficient protection of serialized SSL context or session structures allows an attacker who can modify the serialized structures to induce memory corruption, leading to arbitrary code execution. This is caused by Incorrect Use of Privileged APIs.

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	mbedtls	sid	`3.6.7-3`	fixed
Debian	mbedtls	forky	`3.6.7-3`	fixed
Debian	mbedtls	trixie	`3.6.6-0.1~deb13u1`	vulnerable
Debian	mbedtls	bookworm	`2.28.3-1`	vulnerable
Cpe	mbedtls	Not reported	Not reported	vulnerable
Cpe	mbed_tls	Not reported	`3.6.6`	fixed
Cpe	mbed_tls	Not reported	Not reported	unknown

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	mbedtls	source	sid	`3.6.6-0.1`	unimportant	Not reported	[1132577]
Debian	mbedtls	source	forky	`3.6.6-0.1`	unimportant	Not reported	[1132577]
Debian	mbedtls	source	trixie	`(unfixed)`	unimportant	Not reported	[1132577]
Debian	mbedtls	source	bookworm	`(unfixed)`	unimportant	Not reported	[1132577]
Cpe	mbed_tls	cpe	Not reported	`3.6.6`	Not reported	Not reported	Not reported

[Debian bug #1132577]

Notes

[trixie] mbedtls: Minor issue [bookworm] mbedtls: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libmbedcrypto7]Affected
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
[libmbedtls14]Affected
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
[libmbedtls-dev]Affected
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
[libmbedtls-doc]Affected
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · all · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
- 2.28.3-1 · all · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
[libmbedx509-1]Affected
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Affected
  nvd · mbedtls · debian · bookworm; nvd · mbedtls · debian · 12

[Debian 13 (Trixie)]

[libmbedcrypto16]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Affected
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected
  nvd · mbedtls · debian · 13
[libmbedtls21]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Affected
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected
  nvd · mbedtls · debian · 13
[libmbedtls-dev]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Affected
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected
  nvd · mbedtls · debian · 13
[libmbedtls-doc]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · all · trixie
  Affected
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · all · trixie
  Affected
  nvd · mbedtls · debian · 13
[libmbedx509-7]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Affected
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected
  nvd · mbedtls · debian · 13

Observed: Oct 23, 2026, 10:35:48 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]