---
id: "CVE-2026-128241"
page: "https://infrastack.ai/live/CVE-2026-128241"
kind: "vulnerability"
aliases: ["CVE-2026-128241"]
title: "libexpat xmlwf: symlink following lets local users overwrite files"
severity: "medium"
cvss: 4.4
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "libexpat", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["libexpat", "local-users", "other", "xmlwf"]
not_affected_if: ["no-local-untrusted-users", "xmlwf-not-used-with-d-mode"]
published_at: "2026-11-13T10:18:12+00:00"
first_seen_at: "2026-11-13T10:47:33+00:00"
updated_at: "2026-11-13T10:58:49+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-128241", "first_seen_at": "2026-11-13T10:47:33+00:00"}]
exploit_sources: []
---

# libexpat xmlwf: symlink following lets local users overwrite files

Link for people: https://infrastack.ai/live/CVE-2026-128241 (this .md is for agents)

The xmlwf tool in libexpat through 2.10.0 opens output files with fopen("wb") in its -d mode, which follows symbolic links. A local attacker with write access to the output directory can plant a symlink to truncate or overwrite files writable by the user running xmlwf.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:libexpat affected range not listed fixed no fixed version listed

## Timeline

- 2026-11-13T10:47:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-128241

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/libexpat-xmlwf-through-2.10.0-symlink-following-via-d-output-directory

## From the sources

The xmlwf tool in libexpat through 2.10.0 contains a symlink following vulnerability because -d output mode opens files with fopen("wb"), which follows symbolic links. Local attackers with write access to the output directory can plant a symlink at the expected output name to truncate or overwrite files writable by the xmlwf user.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_