| Name | CVE-2026-27171 |
| Description | zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition. |
| 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 | DSA-6613-1 |
| Debian Bugs | 1128336 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| zlib (PTS) | bookworm | 1:1.2.13.dfsg-1 | vulnerable |
| trixie | 1:1.3.dfsg+really1.3.1-1 | vulnerable |
| trixie (security) | 1:1.3.dfsg+really1.3.1-1+deb13u1 | fixed |
| forky, sid | 1:1.3.dfsg+really1.3.2-4 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| zlib | source | bullseye | (not affected) | | | |
| zlib | source | trixie | 1:1.3.dfsg+really1.3.1-1+deb13u1 | | DSA-6613-1 | |
| zlib | source | (unstable) | 1:1.3.dfsg+really1.3.2-1 | | | 1128336 |
Notes
[bookworm] - zlib <no-dsa> (Minor issue)
[bullseye] - zlib <not-affected> (Affected code implemented later)
https://github.com/madler/zlib/issues/904
Fixed by: https://github.com/madler/zlib/commit/ba829a458576d1ff0f26fc7230c6de816d1f6a77 (v1.3.2)
Introduced with: https://github.com/madler/zlib/commit/f8719f5ae5acdc31d3794ddfea8ac963359de41e (v1.2.12)