DEBIAN-CVE-2026-69186
c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_parse() trusts the attacker-controlled ANCOUNT, NSCOUNT, and ARCOUNT fields before confirming that the DNS response contains enough bytes for the claimed records. Because process_answer() invokes parsing before transaction ID and question validation, a malicious DNS response can cause ares_dns_record_rr_prealloc() and ares_array_set_size() to reserve disproportionate heap memory for a tiny message. Repeated responses create large allocation and release cycles that can degrade or deny name resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7.
DEBIAN-CVE-2026-69186
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-2026-69186
c-ares
Source reference: /affected/0/package/name
- Affected versions
- 1.34.5-1
Source reference:
/affected/0/versions1.34.5-1+deb13u1Source reference:
/affected/0/versions1.34.6-1Source reference:
/affected/0/versions1.34.7-1Source reference:
/affected/0/versions1.34.8-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
c-ares
Source reference: /affected/1/package/name
- Affected versions
- 1.34.5-1
Source reference:
/affected/1/versions1.34.6-1Source reference:
/affected/1/versions - Fixed versions
- 1.34.7-1
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": "c-ares",
"purl": "pkg:deb/debian/c-ares?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.34.5-1",
"1.34.5-1+deb13u1",
"1.34.6-1",
"1.34.7-1",
"1.34.8-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-69186.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.34.7-1"
}
]
}
],
"package": {
"name": "c-ares",
"purl": "pkg:deb/debian/c-ares?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.34.5-1",
"1.34.6-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-69186.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #6073 · Revision 1
- Added to Heist Feed
- Publisher date