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CVE-2026-86138

7.8, high

Xmlsoft libxml2 Integer Overflow Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
7.8, high high CVSS v3.1
EPSS, next 30 days
0.1% higher than 2.4% of scored CVEs
Exploitation
No public evidence
Published
5 Sept 2026a month ago

Description

In libxml2 before 2.15.4, xmlDictAddQString in dict.c has an integer overflow and resultant heap-based buffer overflow.

Details

Vendor
Xmlsoft
Product
libxml2
Weakness
CWE-190 (opens in a new tab)
Status
Analyzed
Updated
15 Sept 2026
Assigner
cve@mitre.org

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

References 2

Patches and fixes 1

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Xmlsoft CVEs

Every Xmlsoft CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-86139 Xmlsoft libxml2 Integer Overflow Vulnerability EPSS 0.2% 7.8, high
  • CVE-2026-86140 Xmlsoft libxml2 Stack-based Buffer Overflow Vulnerability EPSS 0.2% 7.8, high
  • CVE-2026-86142 Xmlsoft libxml2 Heap-based Buffer Overflow Vulnerability EPSS 0.2% 7.8, high
  • CVE-2026-86143 In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to reach write… EPSS 0.2% 7.3, high
  • CVE-2026-86144 In xinclude in libxml2 before 2.15.4, xmlXIncludeProcess and xmlXIncludeProcessTree do not propagate parseFlags EPSS 0.2% 7.8, high

Beyond this page

Is CVE-2026-86138 in your network?

This page tells you how dangerous CVE-2026-86138 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.