4.4
MEDIUM CVSS 3.1
CVE-2026-128241
libexpat xmlwf through 2.10.0 Symlink Following via -d Output Directory
Description

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.

INFO

Published Date :

Nov. 13, 2026, 10:18 a.m.

Last Modified :

Nov. 13, 2026, 10:18 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-128241 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 Libexpat_project libexpat
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 MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update libexpat to a version that fixes the symbolic link following vulnerability.
  • Update libexpat to version 2.10.1 or later.
  • Ensure output directories are protected from symbolic links.
  • Validate file permissions on output directories.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-128241 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-2026-128241 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).

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

The following list is the news that have been mention CVE-2026-128241 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-128241 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.

  • New CVE Received by [email protected]

    Nov. 13, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V4.0 AV:L/AC:H/AT:P/PR:L/UI:P/VC:N/VI:H/VA:N/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:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:N
    Added CWE CWE-59
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/128xxx/CVE-2026-128241.json">CVE-2026-128241</a>
    Added Reference https://github.com/libexpat/libexpat
    Added Reference https://github.com/libexpat/libexpat/blob/R_2_10_0/expat/xmlwf/xmlwf.c#L1272-L1275
    Added Reference https://github.com/libexpat/libexpat/blob/R_2_10_0/expat/xmlwf/xmlwf.c#L1338-L1347
    Added Reference https://github.com/libexpat/libexpat/pull/1502
    Added Reference https://www.vulncheck.com/advisories/libexpat-xmlwf-through-2.10.0-symlink-following-via-d-output-directory
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.