| Name | CVE-2026-69184 |
| Description | c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_name_parse() enforces backward DNS compression pointers but does not bound the total pointer hops or assembled name length. A malicious DNS server can send a response containing a long descending pointer chain and many resource records whose NAME or RDATA fields refer to the chain, causing repeated decompression work that grows quadratically with message size. A single crafted response can stall the single-threaded c-ares event loop and deny DNS resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7. |
| 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) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| c-ares (PTS) | bookworm | 1.18.1-3 | fixed |
| trixie (security), trixie | 1.34.5-1+deb13u1 | vulnerable | |
| forky | 1.34.8-1 | fixed | |
| sid | 1.34.9-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| c-ares | source | bullseye | (not affected) | |||
| c-ares | source | bookworm | (not affected) | |||
| c-ares | source | (unstable) | 1.34.7-1 |
[trixie] - c-ares <no-dsa> (Minor issue)
[bookworm] - c-ares <not-affected> (Vulnerable 1.34 DNS-name decompression parser (src/lib/record/ares_dns_name.c, ares_buf) not present)
[bullseye] - c-ares <not-affected> (Vulnerable 1.34 DNS-name decompression parser not present)
https://www.openwall.com/lists/oss-security/2026/07/06/8
https://github.com/c-ares/c-ares/security/advisories/GHSA-pjmc-gx33-gc76
Fixed by: https://github.com/c-ares/c-ares/commit/f1288bbc70e9a1e0a77134c2382157e52d326aea (main)
Fixed by: https://github.com/c-ares/c-ares/commit/5c8341ba6ff3a8e4e4dfd616f8ed0418838b8b7b (v1.34.7)