---
id: CVE-2026-123202
title: libnxml before 0.18.6 Stack-based Buffer Overflow via long multi-byte XML name
summary: >-
  libnxml before 0.18.6 contains a stack-based buffer overflow vulnerability in
  src/nxml_parser.c that allows remote attackers to write past a 1024-byte stack
  buffer via long XML names. Attackers can supply XML or RSS feeds with a
  1022-cha…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-121
vendor: bakulf
product: libnxml
affected:
  - libnxml < 0.18.6
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-11-05T19:04:41.118484Z'
published: '2026-11-05'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T19:04:52.864Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123202'
references:
  - url: >-
      https://github.com/bakulf/libnxml/commit/fbac242374883edf2ec14127ca6d2accf4704b6a
  - url: 'https://github.com/bakulf/libnxml/releases/tag/0.18.6'
    label: libnxml 0.18.6 Release Notes
  - url: >-
      https://github.com/bakulf/libnxml/blob/9272d1cd6fee88fe7fd4fd812736d95a6ba25f2f/src/nxml_parser.c#L952-L958
  - url: >-
      https://www.vulncheck.com/advisories/libnxml-before-0.18.6-stack-based-buffer-overflow-via-long-multi-byte-xml-name
    label: >-
      VulnCheck Advisory: libnxml before 0.18.6 Stack-based Buffer Overflow via
      long multi-byte XML name
tags:
  - cve.org
ingestedAt: '2026-11-05T22:38:31.502Z'
---

## Overview

libnxml before 0.18.6 contains a stack-based buffer overflow vulnerability in src/nxml_parser.c that allows remote attackers to write past a 1024-byte stack buffer via long XML names. Attackers can supply XML or RSS feeds with a 1022-character element, attribute, DOCTYPE or entity name ending in a multi-byte UTF-8 character to crash parsing applications.

## Affected

- `libnxml < 0.18.6`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.