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DEBIAN-CVE-2026-9679

Type: advisorySource: OSV1 source record

Impact: undici's cookie parser in parseSetCookie percent-decodes cookie values via qsUnescape, turning encoded sequences like %0D%0A, %00, %3B, and %3D into their literal byte equivalents. RFC 6265 §5.4 does not specify any decoding and browsers do not decode either. Applications that parse a Set-Cookie header and then forward the parsed value into a response header (proxies, middleware, SSR frameworks) become vulnerable to HTTP response header injection: an attacker-controlled upstream can inject arbitrary Set-Cookie, Location, or Cache-Control headers into the application's downstream response, enabling session fixation, open redirect, or cache poisoning. Affected applications are those that use undici's cookie parsing (parseSetCookie, parseCookie, getSetCookies) and forward the parsed cookie value into a response header. This was introduced in undici 7.0.0 via PR #3789. Patches: Upgrade to undici v6.26.0, v7.28.0 or v8.5.0. Workarounds: If upgrade is not immediately possible, do not forward values returned by parseSetCookie/parseCookie/getSetCookies directly into response headers; sanitize the value first to strip or reject CR, LF, NUL, ;, and = bytes.

Announced Group revision 1
Original source ↗

DEBIAN-CVE-2026-9679

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-2026-9679

node-undici

Source reference: /affected/0/package/name

Affected versions
7.15.0+dfsg+~cs3.2.0-1

Source reference: /affected/0/versions

7.15.0+dfsg+~cs3.2.0-3

Source reference: /affected/0/versions

7.16.0+dfsg+~cs3.2.0-1

Source reference: /affected/0/versions

7.16.0+dfsg+~cs3.2.0-2

Source reference: /affected/0/versions

7.18.2+dfsg+~cs3.2.0-1

Source reference: /affected/0/versions

7.24.5+dfsg+~cs3.2.0-1

Source reference: /affected/0/versions

7.24.6+dfsg+~cs3.2.0-1

Source reference: /affected/0/versions

7.24.6+dfsg+~cs3.2.0-2

Source reference: /affected/0/versions

7.24.6+dfsg+~cs3.2.0-3

Source reference: /affected/0/versions

7.3.0+dfsg1+~cs24.12.11-1

Source reference: /affected/0/versions

7.3.0+dfsg1+~cs24.12.11-2

Source reference: /affected/0/versions

8.10.2+dfsg+~cs3.2.2-1

Source reference: /affected/0/versions

8.5.0+dfsg+~cs3.2.0-1

Source reference: /affected/0/versions

8.5.0+dfsg+~cs3.2.0-2

Source reference: /affected/0/versions

8.5.0+dfsg+~cs3.2.0-3

Source reference: /affected/0/versions

8.9.0+dfsg+~cs3.2.0-1

Source reference: /affected/0/versions

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

node-undici

Source reference: /affected/1/package/name

Affected versions
7.15.0+dfsg+~cs3.2.0-1

Source reference: /affected/1/versions

7.15.0+dfsg+~cs3.2.0-3

Source reference: /affected/1/versions

7.16.0+dfsg+~cs3.2.0-1

Source reference: /affected/1/versions

7.16.0+dfsg+~cs3.2.0-2

Source reference: /affected/1/versions

7.18.2+dfsg+~cs3.2.0-1

Source reference: /affected/1/versions

7.24.5+dfsg+~cs3.2.0-1

Source reference: /affected/1/versions

7.24.6+dfsg+~cs3.2.0-1

Source reference: /affected/1/versions

7.24.6+dfsg+~cs3.2.0-2

Source reference: /affected/1/versions

7.24.6+dfsg+~cs3.2.0-3

Source reference: /affected/1/versions

7.3.0+dfsg1+~cs24.12.11-1

Source reference: /affected/1/versions

7.3.0+dfsg1+~cs24.12.11-2

Source reference: /affected/1/versions

Fixed versions
8.5.0+dfsg+~cs3.2.0-1

Source reference: /affected/1/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": "node-undici",
      "purl": "pkg:deb/debian/node-undici?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "7.15.0+dfsg+~cs3.2.0-1",
      "7.15.0+dfsg+~cs3.2.0-3",
      "7.16.0+dfsg+~cs3.2.0-1",
      "7.16.0+dfsg+~cs3.2.0-2",
      "7.18.2+dfsg+~cs3.2.0-1",
      "7.24.5+dfsg+~cs3.2.0-1",
      "7.24.6+dfsg+~cs3.2.0-1",
      "7.24.6+dfsg+~cs3.2.0-2",
      "7.24.6+dfsg+~cs3.2.0-3",
      "7.3.0+dfsg1+~cs24.12.11-1",
      "7.3.0+dfsg1+~cs24.12.11-2",
      "8.10.2+dfsg+~cs3.2.2-1",
      "8.5.0+dfsg+~cs3.2.0-1",
      "8.5.0+dfsg+~cs3.2.0-2",
      "8.5.0+dfsg+~cs3.2.0-3",
      "8.9.0+dfsg+~cs3.2.0-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-9679.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "8.5.0+dfsg+~cs3.2.0-1"
          }
        ]
      }
    ],
    "package": {
      "name": "node-undici",
      "purl": "pkg:deb/debian/node-undici?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "7.15.0+dfsg+~cs3.2.0-1",
      "7.15.0+dfsg+~cs3.2.0-3",
      "7.16.0+dfsg+~cs3.2.0-1",
      "7.16.0+dfsg+~cs3.2.0-2",
      "7.18.2+dfsg+~cs3.2.0-1",
      "7.24.5+dfsg+~cs3.2.0-1",
      "7.24.6+dfsg+~cs3.2.0-1",
      "7.24.6+dfsg+~cs3.2.0-2",
      "7.24.6+dfsg+~cs3.2.0-3",
      "7.3.0+dfsg1+~cs24.12.11-1",
      "7.3.0+dfsg1+~cs24.12.11-2"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-9679.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#58417 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement

Revision history

  1. DEBIAN-CVE-2026-9679 · Revision 1Source updated