| Name | CVE-2026-0865 |
| Description | User-controlled header names and values containing newlines can allow injecting HTTP headers. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-4455-1 |
| Debian Bugs | 1126739, 1126740, 1126741, 1126742 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| jython (PTS) | bullseye | 2.7.2+repack1-3 | vulnerable |
| forky, sid, bookworm, trixie | 2.7.3+repack1-1 | vulnerable |
| pypy3 (PTS) | bullseye | 7.3.5+dfsg-2+deb11u2 | vulnerable |
| bullseye (security) | 7.3.5+dfsg-2+deb11u5 | vulnerable |
| bookworm | 7.3.11+dfsg-2+deb12u3 | vulnerable |
| trixie | 7.3.19+dfsg-2 | vulnerable |
| forky, sid | 7.3.20+dfsg-4 | vulnerable |
| python2.7 (PTS) | bullseye | 2.7.18-8+deb11u1 | vulnerable |
| python3.11 (PTS) | bookworm | 3.11.2-6+deb12u6 | vulnerable |
| bookworm (security) | 3.11.2-6+deb12u3 | vulnerable |
| python3.13 (PTS) | trixie | 3.13.5-2 | vulnerable |
| forky, sid | 3.13.12-1 | fixed |
| python3.14 (PTS) | forky, sid | 3.14.3-1 | fixed |
| python3.9 (PTS) | bullseye | 3.9.2-1 | vulnerable |
| bullseye (security) | 3.9.2-1+deb11u5 | fixed |
The information below is based on the following data on fixed versions.
Notes
[trixie] - python3.13 <no-dsa> (Minor issue)
[bookworm] - python3.11 <no-dsa> (Minor issue)
[bullseye] - python2.7 <end-of-life> (EOL in bullseye LTS)
[trixie] - pypy3 <no-dsa> (Minor issue)
[bookworm] - pypy3 <no-dsa> (Minor issue)
[bullseye] - pypy3 <postponed> (Minor issue)
[trixie] - jython <no-dsa> (Minor issue)
[bookworm] - jython <no-dsa> (Minor issue)
[bullseye] - jython <end-of-life> (EOL in bullseye LTS)
https://github.com/python/cpython/pull/143917
https://github.com/python/cpython/issues/143916
https://mail.python.org/archives/list/security-announce@python.org/thread/BJ6QPHNSHJTS3A7CFV6IBMCAP2DWRVNT/
https://github.com/python/cpython/commit/f7fceed79ca1bceae8dbe5ba5bc8928564da7211 (main)
https://github.com/python/cpython/commit/23e3c0ae867cca0130e441e776c9955b9027c510 (3.14-branch)
https://github.com/python/cpython/commit/22e4d55285cee52bc4dbe061324e5f30bd4dee58 (3.13-branch)
https://github.com/python/cpython/commit/4802b96a2cde58570c24c13ef3289490980961c5 (3.12-branch)
https://github.com/python/cpython/commit/e4846a93ac07a8ae9aa18203af0dd13d6e7a6995 (3.11-branch)
https://github.com/python/cpython/commit/2f840249550e082dc351743f474ba56da10478d2 (3.10-branch)
Regression: https://github.com/python/cpython/pull/144118
wsgiref limited security support: https://github.com/python/cpython/issues/144484