CVE catalog

CVE-2026-34872

Severity: Critical · CVSS 9.1
Published: Apr 1, 2026, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.20% · Oct 25, 2026

An issue was discovered in Mbed TLS 3.5.x and 3.6.x through 3.6.5 and TF-PSA-Crypto 1.0. There is a lack of contributory behavior in FFDH due to improper input validation. Using finite-field Diffie-Hellman, the other party can force the shared secret into a small set of values (lack of contributory behavior). This is a problem for protocols that depend on contributory behavior (which is not the case for TLS). The attack can be carried by the peer, or depending on the protocol by an active network attacker (person in the middle).

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`	fixed
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	tf-psa-crypto	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`	not yet assigned	Not reported	[1132577]
Debian	mbedtls	source	forky	`3.6.6-0.1`	not yet assigned	Not reported	[1132577]
Debian	mbedtls	source	trixie	`3.6.6-0.1~deb13u1`	not yet assigned	Not reported	[1132577]
Debian	mbedtls	source	bookworm	`(unfixed)`	not yet assigned	Not reported	[1132577]
Cpe	mbed_tls	cpe	Not reported	`3.6.6`	Not reported	Not reported	Not reported

[Debian bug #1132577]

Notes

[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 · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
[libmbedtls21]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
[libmbedtls-dev]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
[libmbedtls-doc]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · all · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · all · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
[libmbedx509-7]Affected
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Affected · Fixed: 3.6.6-0.1~deb13u1
  nvd · mbedtls · debian · 13

Observed: Oct 23, 2026, 10:35:53 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]