CVE-2026-41401

MEDIUM

libyang - Heap Use-After-Free Write in XML Metadata Parsing

Title source: cna

Description

libyang before 5.2.6 contains a heap use-after-free write vulnerability in lyd_parser_set_data_flags that incorrectly updates metadata list pointers when freeing non-head default metadata entries. Attackers can trigger this vulnerability by submitting crafted YANG XML documents with specific metadata attributes to applications parsing untrusted XML data, causing process crashes or potential code execution.

References (4)

Core 4

Core References

Vendor Advisory vendor-advisory

GHSA Advisory GHSA-9f49-8x56-jmjc

https://github.com/CESNET/libyang/security/advisories/GHSA-9f49-8x56-jmjc

Patch patch

https://github.com/CESNET/libyang/commit/6b5ed47ee674fbe86b31bbebc4ff26889aeff38c

View Patch ZIP pw:eip

Third Party Advisory third-party-advisory

Anthropic CVD Finding ANT-2026-TZQ1KH7E

https://red.anthropic.com/2026/cvd/findings/ANT-2026-TZQ1KH7E

Third Party Advisory third-party-advisory

VulnCheck Advisory: libyang - Heap Use-After-Free Write in XML Metadata Parsing

https://www.vulncheck.com/advisories/libyang-heap-use-after-free-write-in-xml-metadata-parsing

Scores

CVSS v3 6.5

EPSS 0.0052

EPSS Percentile 39.8%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment

Exploitation poc

Automatable no

Technical Impact partial

Details

CWE

CWE-416

Status published

Products (2)

libyang/libyang < 5.4.3

libyang/libyang 5.4.3

Published May 26, 2026

Tracked Since May 26, 2026