Cyber Posture

CVE-2026-41401

MediumPublic PoC
Microsoft: not affectedMSmacOS: not affectedMacLinux: not affectedLnxMobile: not affectedMobNetwork: not affectedNetApplication: not affectedAppOther: affectedOth

Published: 26 May 2026

Published
26 May 2026
Modified
26 May 2026
KEV Added
—
Patch
—
CVSS Score 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0003 9.5th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-41401 is a medium-severity Use After Free (CWE-416) vulnerability in Anthropic (inferred from references). Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 9.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190).
Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-416

Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Why these techniques?

Use-after-free in XML/YANG parser directly enables remote code execution or DoS via crafted untrusted input to public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD 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…

more

parsing untrusted XML data, causing process crashes or potential code execution.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
CWE-416

Affected Products

Anthropic
—
inferred from references and description; NVD did not file a CPE for this CVE

EU & UK References

References