UnratedFix available

DEBIAN-CVE-2026-34872

Type: advisorySource: OSV1 source record

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).

Announced 1 Apr 2026Group revision 1

Original source ↗

DEBIAN-CVE-2026-34872

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-34872

mbedtls

Source reference: /affected/0/package/name

Affected versions: 2.28.3-1
Source reference: /affected/0/versions
2.28.4-1
Source reference: /affected/0/versions
2.28.5-1
Source reference: /affected/0/versions
2.28.6-1
Source reference: /affected/0/versions
2.28.7-1
Source reference: /affected/0/versions
2.28.7-1.1
Source reference: /affected/0/versions
2.28.7-1.1~exp1
Source reference: /affected/0/versions
2.28.8-1
Source reference: /affected/0/versions
3.6.0-1
Source reference: /affected/0/versions
3.6.0-2
Source reference: /affected/0/versions
3.6.0-3
Source reference: /affected/0/versions
3.6.2-1
Source reference: /affected/0/versions
3.6.2-2
Source reference: /affected/0/versions
3.6.2-3
Source reference: /affected/0/versions
3.6.3-1
Source reference: /affected/0/versions
3.6.4-1
Source reference: /affected/0/versions
3.6.4-2
Source reference: /affected/0/versions
3.6.5-0.1
Source reference: /affected/0/versions
3.6.5-0.1~deb13u1
Source reference: /affected/0/versions
3.6.6-0.1
Source reference: /affected/0/versions
3.6.6-0.1~deb13u1
Source reference: /affected/0/versions
3.6.7-2
Source reference: /affected/0/versions
3.6.7-3
Source reference: /affected/0/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

mbedtls

Source reference: /affected/1/package/name

Affected versions: 3.6.4-2
Source reference: /affected/1/versions
3.6.5-0.1
Source reference: /affected/1/versions
3.6.5-0.1~deb13u1
Source reference: /affected/1/versions
Fixed versions: 3.6.6-0.1~deb13u1
Source reference: /affected/1/ranges
Prerequisites: Not stated in this record

mbedtls

Source reference: /affected/2/package/name

Affected versions: 3.6.4-2
Source reference: /affected/2/versions
3.6.5-0.1
Source reference: /affected/2/versions
3.6.5-0.1~deb13u1
Source reference: /affected/2/versions
3.6.6-0.1~deb13u1
Source reference: /affected/2/versions
Fixed versions: 3.6.6-0.1
Source reference: /affected/2/ranges
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "mbedtls",
      "purl": "pkg:deb/debian/mbedtls?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "2.28.3-1",
      "2.28.4-1",
      "2.28.5-1",
      "2.28.6-1",
      "2.28.7-1",
      "2.28.7-1.1",
      "2.28.7-1.1~exp1",
      "2.28.8-1",
      "3.6.0-1",
      "3.6.0-2",
      "3.6.0-3",
      "3.6.2-1",
      "3.6.2-2",
      "3.6.2-3",
      "3.6.3-1",
      "3.6.4-1",
      "3.6.4-2",
      "3.6.5-0.1",
      "3.6.5-0.1~deb13u1",
      "3.6.6-0.1",
      "3.6.6-0.1~deb13u1",
      "3.6.7-2",
      "3.6.7-3"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34872.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "3.6.6-0.1~deb13u1"
          }
        ]
      }
    ],
    "package": {
      "name": "mbedtls",
      "purl": "pkg:deb/debian/mbedtls?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "3.6.4-2",
      "3.6.5-0.1",
      "3.6.5-0.1~deb13u1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34872.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "3.6.6-0.1"
          }
        ]
      }
    ],
    "package": {
      "name": "mbedtls",
      "purl": "pkg:deb/debian/mbedtls?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "3.6.4-2",
      "3.6.5-0.1",
      "3.6.5-0.1~deb13u1",
      "3.6.6-0.1~deb13u1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-34872.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #56397 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 16:35:57 GMT
Publisher date: Wed, 01 Apr 2026 20:16:27 GMT

Read the original announcement

Revision history

25 Oct 2026DEBIAN-CVE-2026-34872 · Revision 1Source updated