7.1
HIGH CVSS 4.0
CVE-2026-41401
libyang - Heap Use-After-Free Write in XML Metadata Parsing
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.

INFO

Published Date :

May 26, 2026, 3:16 p.m.

Last Modified :

May 26, 2026, 7:47 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-41401 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Cesnet libyang
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update libyang to version 5.2.6 or later to fix heap use-after-free.
  • Update libyang to version 5.2.6 or later.
  • Apply vendor-supplied patches for libyang.
  • Validate XML data before parsing.
Public PoC/Exploit Available at Github

CVE-2026-41401 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-41401 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-41401 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Tracking Vulnerabilities That Appear to be Credited to the Anthropic Research Team

Updated: 1 week, 2 days ago
21 stars 3 fork 3 watcher
Born at : April 17, 2026, 4:15 p.m. This repo has been linked 83 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-41401 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-41401 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    May. 26, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/CESNET/libyang/security/advisories/GHSA-9f49-8x56-jmjc
    Added Reference https://red.anthropic.com/2026/cvd/findings/ANT-2026-TZQ1KH7E
  • New CVE Received by [email protected]

    May. 26, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-416
    Added Reference https://github.com/CESNET/libyang/commit/6b5ed47ee674fbe86b31bbebc4ff26889aeff38c
    Added Reference https://github.com/CESNET/libyang/security/advisories/GHSA-9f49-8x56-jmjc
    Added Reference https://red.anthropic.com/2026/cvd/findings/ANT-2026-TZQ1KH7E
    Added Reference https://www.vulncheck.com/advisories/libyang-heap-use-after-free-write-in-xml-metadata-parsing
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.