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Fencer Vulns
high 7.5

CVE-2025-6985 json

XXE Vulnerability in langchain-ai/langchain

published 2025-10-06 13 mo ago modified 2026-10-19 20 d ago also GHSA-m42m-m8cr-8m58 , PYSEC-2026-1520 , EUVD-2025-31884

cvss
7.5
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

The HTMLSectionSplitter class in langchain-text-splitters version 0.3.8 is vulnerable to XML External Entity (XXE) attacks due to unsafe XSLT parsing. This vulnerability arises because the class allows the use of arbitrary XSLT stylesheets, which are parsed using lxml.etree.parse() and lxml.etree.XSLT() without any hardening measures. In lxml versions up to 4.9.x, external entities are resolved by default, allowing attackers to read arbitrary local files or perform outbound HTTP(S) fetches. In lxml versions 5.0 and above, while entity expansion is disabled, the XSLT document() function can still read any URI unless XSLTAccessControl is applied. This vulnerability allows remote attackers to gain read-only access to any file the LangChain process can reach, including sensitive files such as SSH keys, environment files, source code, or cloud metadata. No authentication, special privileges, or user interaction are required, and the issue is exploitable in default deployments that enable custom XSLT.

Patch / fix

  • pypi langchain-text-splitters 0.3.9

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-6985 updated cvss 7.5

langchain-text-splitters: XXE Vulnerability in langchain-text-splitters

  • Red Hat Ansible Automation Platform 2 ansible-automation-platform-24/lightspeed-rhel8, ansible-automation-platform-26/lightspeed-rhel9
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AI (RHEL AI) rhelai1/bootc-amd-rhel9, rhelai1/bootc-intel-rhel9, rhelai1/bootc-nvidia-rhel9, rhelai1/bootc-azure-amd-rhel9, rhelai1/instructlab-amd-rhel9, rhelai1/bootc-aws-nvidia-rhel9, +4 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Ansible Automation Platform 2.5 for RHEL 8 ansible-automation-platform-25/lightspeed-rhel8 2.5.250924-2
    fixed: vendor fix RHSA-2025:18984
  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-service-api-rhel9 Red Hat Ansible Automation Platform 2 ansible-automation-platform/ee-minimal-rhel8, ansible-automation-platform/ee-minimal-rhel9, ansible-automation-platform-24/de-minimal-rhel8, ansible-automation-platform-24/de-minimal-rhel9, ansible-automation-platform-24/ee-minimal-rhel8, ansible-automation-platform-24/ee-minimal-rhel9, +25 more Red Hat Ansible Automation Platform 2.5 for RHEL 8 ansible-automation-platform-25/hub-rhel8 4.10.9-1, ansible-automation-platform-25/hub-web-rhel8 4.10.9-1, ansible-automation-platform-25/receptor-rhel8 1.6.0-1, ansible-automation-platform-25/de-minimal-rhel8 1.1.7-14, ansible-automation-platform-25/controller-rhel8 4.6.21-13, ansible-automation-platform-25/ee-minimal-rhel8 1.0.0-982, +26 more Red Hat Ansible Automation Platform 2.5 for RHEL 9 ansible-automation-platform-25/de-minimal-rhel9 1.1.7-15, ansible-automation-platform-25/ee-minimal-rhel9 1.0.0-983, ansible-automation-platform-25/de-supported-rhel9 1.1.7-13, ansible-automation-platform-25/ee-supported-rhel9 1.0.0-1108, ansible-automation-platform-25/ansible-builder-rhel9 3.1.0-260, ansible-automation-platform-25/ee-cloud-services-rhel9 1.0.0-316, +2 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
OSV 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi langchain-text-splitters
<0.3.9
0.3.9

Affected products

  • langchain-ai langchain-ai/langchain

Classification

Weakness
  • CWE-611 Improper Restriction of XML External Entity Reference

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.