CVE-2026-112273
Received Received - Intake

Heap Out-of-Bounds Read in libtins DNS Parser

Publication date: 2026-10-19

Last updated on: 2026-10-19

Assigner: VulnCheck

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.

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Meta Information

Published
2026-10-19
Last Modified
2026-10-19
Generated
2026-10-19
AI Q&A
2026-10-19
EPSS Evaluated
N/A
NVD
CVE-2026-112273
EUVD
EUVD-2026-104300

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
libtins libtins 0

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-125 The product reads data past the end, or before the beginning, of the intended buffer.

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Executive Summary

CVE-2026-112273 is a heap out-of-bounds read vulnerability in the libtins library affecting versions through 4.6. It occurs in the DNS::compose_name function in src/dns.cpp where improper handling of DNS domain name parsing allows reading one byte past the packet buffer. This happens when a DNS label ends exactly at the packet boundary, causing the function to dereference a one-past-the-end position during parsing.

Detection Guidance

Detecting this vulnerability requires monitoring DNS packet parsing in libtins-based applications. Use network traffic analysis tools like Wireshark to inspect DNS packets for malformed labels or labels ending exactly at packet boundaries. Check application logs for crashes during DNS parsing. Monitor for heap corruption errors in applications using libtins 4.6 or earlier.

Impact Analysis

This vulnerability can cause applications using libtins to crash when processing malformed DNS packets. While it does not lead to code execution or information leaks, crashes may disrupt services relying on libtins for network packet handling. Systems using hardened memory allocators are particularly affected as they may terminate the application upon detecting the out-of-bounds read.

Mitigation Strategies

Upgrade libtins to a patched version beyond 4.6. If upgrading is not possible, implement input validation for DNS packets to reject malformed labels. Disable DNS parsing in affected applications if not critical. Monitor network traffic for suspicious DNS packets with labels ending at boundaries.

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