DEBIAN-CVE-2026-33630
c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares' query-completion handling. The same flaw — a query's callback being invoked while the query is still linked in the channel's internal lookup structures — is present at multiple points in the resend/finish path (timeout handling, response handling, and query dispatch). If the query, or for ares_getaddrinfo() the owning host_query, is freed as a side effect of that callback, it is then accessed and/or freed a second time. This vulnerability is fixed in ver 1.34.7.
DEBIAN-CVE-2026-33630
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-2026-33630
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-2026-33630.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-2026-33630.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56840 · Revision 1
- Added to Heist Feed
- Publisher date