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DEBIAN-CVE-2026-19773

Type: advisorySource: OSV1 source record

libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of libwebsockets. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of HTTP/2 HPACK path header. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-31036.

Announced Source revision 1
Original source ↗

DEBIAN-CVE-2026-19773

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-2026-19773

libwebsockets

Source reference: /affected/0/package/name

Affected versions
4.1.6-3

Source reference: /affected/0/versions

4.1.6-3.1

Source reference: /affected/0/versions

4.3.2-1

Source reference: /affected/0/versions

4.3.2-2

Source reference: /affected/0/versions

4.3.2-3

Source reference: /affected/0/versions

4.3.2-4

Source reference: /affected/0/versions

4.3.3-1

Source reference: /affected/0/versions

4.3.3-1.1

Source reference: /affected/0/versions

4.3.3-1.1~exp1

Source reference: /affected/0/versions

4.3.5-1

Source reference: /affected/0/versions

4.3.5-2

Source reference: /affected/0/versions

4.3.5-3

Source reference: /affected/0/versions

4.3.5-4

Source reference: /affected/0/versions

4.3.5-4.1

Source reference: /affected/0/versions

4.3.5-5

Source reference: /affected/0/versions

4.3.5-6

Source reference: /affected/0/versions

4.3.5-7

Source reference: /affected/0/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

libwebsockets

Source reference: /affected/1/package/name

Affected versions
4.3.5-1

Source reference: /affected/1/versions

4.3.5-1+deb13u1

Source reference: /affected/1/versions

4.3.5-1+deb13u2

Source reference: /affected/1/versions

Fixed versions
4.3.5-1+deb13u3

Source reference: /affected/1/ranges

Prerequisites
Not stated in this record

libwebsockets

Source reference: /affected/2/package/name

Affected versions
4.3.5-1

Source reference: /affected/2/versions

4.3.5-2

Source reference: /affected/2/versions

4.3.5-3

Source reference: /affected/2/versions

4.3.5-4

Source reference: /affected/2/versions

4.3.5-4.1

Source reference: /affected/2/versions

4.3.5-5

Source reference: /affected/2/versions

4.3.5-6

Source reference: /affected/2/versions

Fixed versions
4.3.5-7

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": "libwebsockets",
      "purl": "pkg:deb/debian/libwebsockets?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "4.1.6-3",
      "4.1.6-3.1",
      "4.3.2-1",
      "4.3.2-2",
      "4.3.2-3",
      "4.3.2-4",
      "4.3.3-1",
      "4.3.3-1.1",
      "4.3.3-1.1~exp1",
      "4.3.5-1",
      "4.3.5-2",
      "4.3.5-3",
      "4.3.5-4",
      "4.3.5-4.1",
      "4.3.5-5",
      "4.3.5-6",
      "4.3.5-7"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-19773.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "4.3.5-1+deb13u3"
          }
        ]
      }
    ],
    "package": {
      "name": "libwebsockets",
      "purl": "pkg:deb/debian/libwebsockets?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "4.3.5-1",
      "4.3.5-1+deb13u1",
      "4.3.5-1+deb13u2"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-19773.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "4.3.5-7"
          }
        ]
      }
    ],
    "package": {
      "name": "libwebsockets",
      "purl": "pkg:deb/debian/libwebsockets?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "4.3.5-1",
      "4.3.5-2",
      "4.3.5-3",
      "4.3.5-4",
      "4.3.5-4.1",
      "4.3.5-5",
      "4.3.5-6"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-19773.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#58685 · Revision 1
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Publisher date
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