UBUNTU-CVE-2026-69184

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UBUNTU-CVE-2026-69184

Summary:

Details: 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.

References: https://ubuntu.com/security/CVE-2026-69184, https://www.cve.org/CVERecord?id=CVE-2026-69184, https://www.openwall.com/lists/oss-security/2026/07/06/8, https://github.com/c-ares/c-ares/security/advisories/GHSA-pjmc-gx33-gc76, https://ubuntu.com/security/notices/USN-8951-1