CVE catalog

CVE-2026-50161

libre is a generic library for real-time…

[CVE catalog]

libre is a generic library for real-time communications with asynchronous input and output support. Prior to 4.8.1, the websock_decode() function in src/websock/websock.c contains an integer overflow when validating a masked WebSocket frame that uses the 64-bit extended length encoding. The expression 4 + hdr->len can wrap when hdr->len is close to UINT64_MAX, causing the mbuf_get_left() bounds check to pass. The subsequent XOR unmasking loop then writes beyond the heap buffer. Applications using websock_accept() or websock_accept_proto() to implement a WebSocket server are affected, and exploitation can cause attacker-controlled heap corruption or denial of service after the HTTP WebSocket upgrade handshake. This issue is fixed in version 4.8.1.

Severity
Critical · CVSS 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
Updated
Source
[NVD] · [CVE record]
EPSS
0.72% · Oct 27, 2026

Projects and upstream resources

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Version impact has not been established. The original provider fields are retained below.

Provider details and historical evidence
Original provider fields
{
  "package_releases": [
    {
      "name": "libre",
      "status": "fixed",
      "release": "sid",
      "version": "2.0.1-4"
    },
    {
      "name": "libre",
      "status": "fixed",
      "release": "forky",
      "version": "2.0.1-4"
    },
    {
      "name": "libre",
      "status": "vulnerable",
      "release": "trixie",
      "version": "2.0.1-3"
    },
    {
      "name": "libre",
      "status": "vulnerable",
      "release": "bookworm",
      "version": "1.1.0-1"
    }
  ],
  "fixed_versions": [
    {
      "bug": 1146714,
      "name": "libre",
      "type": "source",
      "origin": null,
      "release": "sid",
      "urgency": "not yet assigned",
      "fixed_version": "2.0.1-4"
    },
    {
      "bug": 1146714,
      "name": "libre",
      "type": "source",
      "origin": null,
      "release": "forky",
      "urgency": "not yet assigned",
      "fixed_version": "2.0.1-4"
    },
    {
      "bug": 1146714,
      "name": "libre",
      "type": "source",
      "origin": null,
      "release": "trixie",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1146714,
      "name": "libre",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": ""
    }
  ],
  "distribution_packages": []
}

[Debian bug #1146714]

Publisher notes

[trixie] libre: Minor issue [bookworm] libre: Minor issue

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

  • [libre0]Unknown

    Source package: [libre]

    Details (2)

    • 1.1.0-1+b2 · amd64 · bookworm

      Affected

      nvd · libre · debian · bookworm; nvd · libre · debian · 12

    • 1.1.0-1+b2 · arm64 · bookworm

      Affected

      nvd · libre · debian · bookworm; nvd · libre · debian · 12

  • [libre-dev]Unknown

    Source package: [libre]

    Details (2)

    • 1.1.0-1+b2 · amd64 · bookworm

      Affected

      nvd · libre · debian · bookworm; nvd · libre · debian · 12

    • 1.1.0-1+b2 · arm64 · bookworm

      Affected

      nvd · libre · debian · bookworm; nvd · libre · debian · 12

[Debian 13 (Trixie)]

  • [libre1]Unknown

    Source package: [libre]

    Details (2)

    • 2.0.1-3 · amd64 · trixie

      Affected

      nvd · libre · debian · 13

    • 2.0.1-3 · arm64 · trixie

      Affected

      nvd · libre · debian · 13

  • [libre-dev]Unknown

    Source package: [libre]

    Details (2)

    • 2.0.1-3 · amd64 · trixie

      Affected

      nvd · libre · debian · 13

    • 2.0.1-3 · arm64 · trixie

      Affected

      nvd · libre · debian · 13

Observed:

References

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