LangChain affected by SSRF via image_url token counting in ChatOpenAI.get_num_tokens_from_messages

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-26013: 0.43% estimated exploitation activity in the next 30 days; percentile 37.27 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Server-Side Request Forgery (SSRF) in ChatOpenAI Image Token Counting Summary The ChatOpenAI.getnumtokensfrommessages() method fetches arbitrary imageurl values without validation when computing token counts for vision-enabled models. This allows attackers to trigger Server-Side Request Forgery (SSRF) attacks by providing malicious image URLs in user input. Severity Low - The vulnerability allows SSRF attacks but has limited impact due to: - Responses are not returned to the attacker (blind SSRF) - Default 5-second timeout limits resource exhaustion - Non-image responses fail at PIL image parsing Impact An attacker who can control image URLs passed to getnumtokensfrommessages() can: - Trigger HTTP requests from the application server to arbitrary internal or external URLs - Cause the server to access internal network resources (private IPs, cloud metadata endpoints) - Cause minor resource consumption through image downloads (bounded by timeout) Note: This vulnerability occurs during…

Published by the source

11 Feb 2026, 14:23 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 13:36 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-2g6r-c272-w58r

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-2g6r-c272-w58r

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# Patch Next advisory brief: CVE-2026-26013

Advisory: LangChain affected by SSRF via image_url token counting in ChatOpenAI.get_num_tokens_from_messages
IDs: CVE-2026-26013, GHSA-2g6r-c272-w58r
Record: https://patchnext.com/advisories/cve-2026-26013 (revision 2, source checked 26 Oct 2026, 13:36 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: langchain-core 1.2.11. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI langchain-core: affected < 1.2.11; fixed in 1.2.11

## Suggested inspection (read-only)
- `python -m pip show langchain-core`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on langchain-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-2g6r-c272-w58r (OSV record GHSA-2g6r-c272-w58r lists affected ranges: PyPI langchain-core >=0 <1.2.11 (fixed))
- Verified: https://github.com/advisories/GHSA-2g6r-c272-w58r (GitHub-reviewed advisory GHSA-2g6r-c272-w58r lists affected ranges: PyPI langchain-core >=0 <1.2.11)

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