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DEBIAN-CVE-2026-23943

Type: advisorySource: OSV1 source record

Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion. The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS. Two compression algorithms are affected: * zlib: Activates immediately after key exchange, enabling unauthenticated attacks * zlib@openssh.com: Activates post-authentication, enabling authenticated attacks Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments. This vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4. This issue affects OTP from OTP 17.0 before OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to ssh from 3.0.1 before 5.5.1, 5.2.11.6 and 5.1.4.14.

Announced Source revision 1
Original source ↗

DEBIAN-CVE-2026-23943

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-2026-23943

erlang

Source reference: /affected/0/package/name

Affected versions
1:25.2.3+dfsg-1

Source reference: /affected/0/versions

1:25.2.3+dfsg-1+deb12u1

Source reference: /affected/0/versions

1:25.2.3+dfsg-1+deb12u2

Source reference: /affected/0/versions

1:25.2.3+dfsg-1+deb12u3

Source reference: /affected/0/versions

Fixed versions
1:25.2.3+dfsg-1+deb12u4

Source reference: /affected/0/ranges

Prerequisites
Not stated in this record

erlang

Source reference: /affected/1/package/name

Affected versions
1:27.3.4.1+dfsg-1

Source reference: /affected/1/versions

1:27.3.4.1+dfsg-1+deb13u1

Source reference: /affected/1/versions

Fixed versions
1:27.3.4.1+dfsg-1+deb13u2

Source reference: /affected/1/ranges

Prerequisites
Not stated in this record

erlang

Source reference: /affected/2/package/name

Affected versions
1:27.3.4.1+dfsg-1

Source reference: /affected/2/versions

1:27.3.4.3+dfsg-1

Source reference: /affected/2/versions

1:27.3.4.4+dfsg-1

Source reference: /affected/2/versions

1:27.3.4.6+dfsg-1

Source reference: /affected/2/versions

1:27.3.4.8+dfsg-1

Source reference: /affected/2/versions

Fixed versions
1:27.3.4.9+dfsg-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"
          },
          {
            "fixed": "1:25.2.3+dfsg-1+deb12u4"
          }
        ]
      }
    ],
    "package": {
      "name": "erlang",
      "purl": "pkg:deb/debian/erlang?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "1:25.2.3+dfsg-1",
      "1:25.2.3+dfsg-1+deb12u1",
      "1:25.2.3+dfsg-1+deb12u2",
      "1:25.2.3+dfsg-1+deb12u3"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23943.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1:27.3.4.1+dfsg-1+deb13u2"
          }
        ]
      }
    ],
    "package": {
      "name": "erlang",
      "purl": "pkg:deb/debian/erlang?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "1:27.3.4.1+dfsg-1",
      "1:27.3.4.1+dfsg-1+deb13u1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23943.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1:27.3.4.9+dfsg-1"
          }
        ]
      }
    ],
    "package": {
      "name": "erlang",
      "purl": "pkg:deb/debian/erlang?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "1:27.3.4.1+dfsg-1",
      "1:27.3.4.3+dfsg-1",
      "1:27.3.4.4+dfsg-1",
      "1:27.3.4.6+dfsg-1",
      "1:27.3.4.8+dfsg-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23943.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#57441 · Revision 1
Added to Heist Feed
Publisher date
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