CVE-2026-112273
libtins through 4.6 Heap Out-of-Bounds Read via DNS::compose_name
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
libtins through 4.6 Heap Out-of-Bounds Read via DNS::compose_name
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.
- Record
CVE-2026-112273- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2026-104300
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.
- Record
EUVD-2026-104300- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-q9cp-6gg7-9cpm
libtins through 4.6 contains a heap out-of-bounds read vulnerability in DNS::compose_name in src...
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.
- Record
GHSA-q9cp-6gg7-9cpm- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-112273- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
OSV
libtins through 4.6 Heap Out-of-Bounds Read via DNS::compose_name
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.
- Record
CVE-2026-112273- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-125
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-112273
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.
- Record
DEBIAN-CVE-2026-112273- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-112273
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.
- Record
UBUNTU-CVE-2026-112273- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libtinsDebian:12 |
All versions, plus listed versions 4.0-14.5-14.5-1.1 |
None known |
libtinsDebian:13 |
All versions, plus listed versions 4.5-14.5-1.1 |
None known |
libtinsDebian:14 |
All versions, plus listed versions 4.5-14.5-1.1 |
None known |
libtinsUbuntu:18.04:LTS |
All versions, plus listed versions 3.4-23.4-2build1 |
None known |
libtinsUbuntu:20.04:LTS |
All versions, plus listed versions 4.0-14.0-1build1 |
None known |
libtinsUbuntu:22.04:LTS |
All versions, plus listed versions 4.0-1build14.0-1build2 |
None known |
libtinsUbuntu:24.04:LTS |
All versions, plus listed versions 4.0-1build24.5-14.5-1build14.5-1build2 |
None known |
libtinsUbuntu:26.10 |
All versions, plus listed versions 4.5-1.14.5-1.1build1 |
None known |
libtinsUbuntu:26.04:LTS |
All versions, plus listed versions 4.5-1build24.5-1.1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-112273 is a medium vulnerability (CVSS 6.9) in Libtins, published October 19, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.56%, the 47th percentile. No source names a fixed version.
References
hackmd.io/@haindpwn/libtins-dns-name-parsing-oob-read
github.com/mfontanini/libtins/blob/v4.6/src/dns.cpp
vulncheck.com/advisories/libtins-through-4.6-heap-out-of-bounds-read-via-dns-compose-name
nvd.nist.gov/vuln/detail/CVE-2026-112273