DEBIAN-CVE-2026-78227
- Source
- https://security-tracker.debian.org/tracker/CVE-2026-78227
- Import Source
- https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-78227.json
- JSON Data
- https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-78227
- Upstream
- Published
- 2026-09-16T09:17:05Z
- Modified
- 2026-09-17T05:00:51Z
- Severity
-
- 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L CVSS Calculator
- Summary
- [none]
- Details
-
NLnet Labs Unbound 1.22.0 up to and including 1.26.1, has a use-after-free vulnerability when compiled for DNS-over-QUIC support with '--with-libngtcp2'. Each DoQ stream owns an output buffer that holds the DNS response. ngtcp2's retransmission buffer keeps a shallow pointer into the output buffer for as long as a STREAM frame may be resent. On a client RESET_STREAM, the output buffer is freed but ngtcp2 still holds the matching retransmission entries. The next PTO timeout makes ngtcp2 re-encode the STREAM frame and copy from the freed buffer. A malicious actor that can query Unbound over DoQ and that withholds ACKs, sends RESET_STREAM, and waits for PTO, reaches this use-after-free with no privilege. This leads to retransmissions against freed memory and eventually an abnormal server exit under a 20-query spray.
- References
Affected packages
Debian:12 / unbound
Package
- Name
- unbound
- Purl
- pkg:deb/debian/unbound?arch=source&distro=bookworm
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected
Debian:13 / unbound
Package
- Name
- unbound
- Purl
- pkg:deb/debian/unbound?arch=source&distro=trixie
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected
Debian:14 / unbound
Package
- Name
- unbound
- Purl
- pkg:deb/debian/unbound?arch=source&distro=forky
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected