id: PYSEC-2026-2558
published: "2026-07-13T15:02:57.378714Z"
modified: "2026-07-13T16:04:29.197675Z"
aliases:
- CVE-2026-7845
- GHSA-wmvv-fhm6-w34x
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.
affected:
- package:
    name: langchain-chatchat
    ecosystem: PyPI
    purl: pkg:pypi/langchain-chatchat
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - last_affected: 0.3.1.3
  versions:
  - 0.3.0
  - 0.3.0.20240506
  - 0.3.0.20240606
  - 0.3.0.20240610
  - 0.3.0.20240610.1
  - 0.3.0.20240611
  - 0.3.0.20240612
  - 0.3.0.20240612.1
  - 0.3.0.20240612.2
  - 0.3.0.20240612.3
  - 0.3.0.20240612.4
  - 0.3.0.20240616
  - 0.3.0.20240618
  - 0.3.0.20240619
  - 0.3.0.20240621
  - 0.3.0.20240621.3
  - 0.3.0.20240625
  - 0.3.0.20240625.1
  - 0.3.1
  - 0.3.1.1
  - 0.3.1.2
  - 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
- type: PACKAGE
  url: https://pypi.org/project/langchain-chatchat
- type: ADVISORY
  url: https://github.com/advisories/GHSA-wmvv-fhm6-w34x
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