CVE-2026-7845: Langchain chatchat Langchain-Chatchat Uses A Broken Or Vulnerability

LOW
Advisory Identifier: GHSA-wmvv-fhm6-w34x
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CVSS 2.6
CWE-327
Published
Advisory Summary

CVE-2026-7845 is a LOW (CVSS 2.6) langchain-chatchat uses a broken or vulnerability (CWE-327: Use of a Broken or Risky Cryptographic Algorithm) affecting Langchain chatchat libraries in the PyPI ecosystem. The issue involves langchain-chatchat uses a broken or risky cryptographic algorithm. Remediation is available in the latest vendor maintenance releases.

CVE-2026-7845 at a Glance

CVE Identifier CVE-2026-7845
GHSA Identifier GHSA-wmvv-fhm6-w34x
Severity LOW
CVSS v3.1 Base Score 2.6
CWE Classification CWE-327: Use of a Broken or Risky Cryptographic Algorithm
Affected Product Langchain chatchat
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 2.6

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N).

Attack Vector Adjacent (AV:A)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-7845

To remediate this vulnerability, upgrade all affected Langchain chatchat dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

langchain-chatchat fixed: Latest secure release 
pip install langchain-chatchat>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show langchain-chatchat

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-7845, inspect your installed packages using pip:

pip show langchain-chatchat

Analyze the terminal output to locate any version of Langchain chatchat in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show langchain-chatchat command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-327: Use of a Broken or Risky Cryptographic Algorithm, where the product uses a broken or risky cryptographic algorithm or protocol. In Langchain chatchat, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A flaw has been found in chatchat-space Langchain-Chatchat up to 0.3.1.3. This issue affects the function PIL.Image.tobytes of the file libs/chatchat-server/chatchat/webui_pages/dialogue/dialogue.py of the component Vision Chat Paste Image Handler. This manipulation of the argument paste_image.image_data causes use of weak hash. The attacker needs to be present on the local network. The attack is considered to have high complexity. The exploitability is assessed as difficult. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.

CVE-2026-7845 Affected Langchain chatchat Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
langchain-chatchat
pypi/langchain-chatchat
PyPI
≤ 0.3.1.3

References

NVD — CVE-2026-7845 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-7845
Langchain chatchat Source Repository REPOSITORY
https://github.com/chatchat-space/Langchain-Chatchat/issues/5462
Langchain chatchat Source Repository REPOSITORY
https://github.com/3em0/cve_repo/blob/main/Langchain-Chatchat/Vuln-1-tobytes-Hash-Collision.md
Langchain chatchat Source Repository REPOSITORY
https://github.com/chatchat-space/Langchain-Chatchat
vuldb.com/submit/807794 WEB
https://vuldb.com/submit/807794
vuldb.com/vuln/361124 WEB
https://vuldb.com/vuln/361124
vuldb.com/vuln/361124/cti WEB
https://vuldb.com/vuln/361124/cti

Frequently Asked Questions

What is CVE-2026-7845?
CVE-2026-7845 is a security vulnerability in Langchain chatchat involving Langchain-Chatchat Uses a Broken or Risky Cryptographic Algorithm under CWE-327: Use of a Broken or Risky Cryptographic Algorithm.
Which Langchain chatchat versions are affected?
Affected versions include releases prior to current release patches across affected packages: langchain-chatchat.
What version fixes CVE-2026-7845?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is langchain-chatchat affected?
Yes, langchain-chatchat is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-7845?
CVE-2026-7845 has a CVSS v3.1 base score of 2.6 (LOW) with vector string CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2026-7845?
CVE-2026-7845 is classified under CWE-327: Use of a Broken or Risky Cryptographic Algorithm (The product uses a broken or risky cryptographic algorithm or protocol.).
How can I check PyPI dependencies for CVE-2026-7845?
Run the dependency tree command: 'pip show langchain-chatchat'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wmvv-fhm6-w34x",
  "modified" : "2026-05-08T22:16:42Z",
  "published" : "2026-05-05T18:33:26Z",
  "aliases" : [ "CVE-2026-7845" ],
  "summary" : "Langchain-Chatchat Uses a Broken or Risky Cryptographic Algorithm",
  "details" : "A flaw has been found in chatchat-space Langchain-Chatchat up to 0.3.1.3. This issue affects the function PIL.Image.tobytes of the file libs/chatchat-server/chatchat/webui_pages/dialogue/dialogue.py of the component Vision Chat Paste Image Handler. This manipulation of the argument paste_image.image_data causes use of weak hash. The attacker needs to be present on the local network. The attack is considered to have high complexity. The exploitability is assessed as difficult. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:A/AC:H/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "langchain-chatchat"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.3.1.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-7845"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chatchat-space/Langchain-Chatchat/issues/5462"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/3em0/cve_repo/blob/main/Langchain-Chatchat/Vuln-1-tobytes-Hash-Collision.md"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/chatchat-space/Langchain-Chatchat"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/submit/807794"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/361124"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/361124/cti"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-327" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-08T22:16:42Z",
    "nvd_published_at" : "2026-05-05T16:16:19Z"
  }
}