Vulnerability · Published Oct 19, 2026 · Assigned by VulnCheck
CVE-2026-112273libtins through 4.6 Heap Out-of-Bounds Read via DNS::compose_name
Medium 5.3
In plain English
A medium-severity out-of-bounds read in libtins from libtins. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities).
Official description
libtins through 4.6 contains a heap out-of-bounds read vulnerability in DNS::compose_name in src/dns.cpp that allows remote attackers to read past the packet buffer by sending a label ending exactly at the packet end. Attackers can deliver crafted DNS packets whose additional, answer, or authority records trigger a one-byte read when parsed, crashing applications on hardened allocators.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libtins | no fix listed | DEBIAN-CVE-2026-112273 |
| Debian:13 | libtins | no fix listed | DEBIAN-CVE-2026-112273 |
| Debian:14 | libtins | no fix listed | DEBIAN-CVE-2026-112273 |
| Ubuntu:22.04:LTS | libtins | no fix listed | UBUNTU-CVE-2026-112273 |
| Ubuntu:24.04:LTS | libtins | no fix listed | UBUNTU-CVE-2026-112273 |
| Ubuntu:26.04:LTS | libtins | no fix listed | UBUNTU-CVE-2026-112273 |
| Ubuntu:26.10 | libtins | no fix listed | UBUNTU-CVE-2026-112273 |
Affected products (as reported)
Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
- https://hackmd.io/@haindpwn/libtins-dns-name-parsing-oob-read third-party-advisory
- https://github.com/mfontanini/libtins/blob/v4.6/src/dns.cpp#L338-L389 technical-description
- https://github.com/mfontanini/libtins product
- VulnCheck Advisory: libtins through 4.6 Heap Out-of-Bounds Read via DNS::compose_name third-party-advisory
- https://hackmd.io/@haindpwn/cve-2026-112273-112274-libtins-dns-name-parsing-oob-read exploit