vLLM has a Weakness in MultiModalHasher Image Hashing Implementation

Exploitation

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

CVSS

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

EPSS

• CVE-2025-46722: 0.34% estimated exploitation activity in the next 30 days; percentile 27.27 (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.

Summary In the file vllm/multimodal/hasher.py, the MultiModalHasher class has a security and data integrity issue in its image hashing method. Currently, it serializes PIL.Image.Image objects using only obj.tobytes(), which returns only the raw pixel data, without including metadata such as the image’s shape (width, height, mode). As a result, two images of different sizes (e.g., 30x100 and 100x30) with the same pixel byte sequence could generate the same hash value. This may lead to hash collisions, incorrect cache hits, and even data leakage or security risks. Details - Affected file: vllm/multimodal/hasher.py - Affected method: MultiModalHasher.serializeitem https://github.com/vllm-project/vllm/blob/9420a1fc30af1a632bbc2c66eb8668f3af41f026/vllm/multimodal/hasher.py#L34-L35 - Current behavior: For Image.Image instances, only obj.tobytes() is used for hashing. - Problem description: obj.tobytes() does not include the image’s width, height, or mode metadata. - Impact: Two images with…

Published by the source

28 May 2025, 18:03 UTC

Last modified by the source

7 Aug 2026, 08:12 UTC

Source last checked

26 Oct 2026, 13:32 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-c65p-x677-fgj6

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-c65p-x677-fgj6

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# Patch Next advisory brief: CVE-2025-46722

Advisory: vLLM has a Weakness in MultiModalHasher Image Hashing Implementation
IDs: CVE-2025-46722, GHSA-c65p-x677-fgj6
Record: https://patchnext.com/advisories/cve-2025-46722 (revision 2, source checked 26 Oct 2026, 13:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vllm 0.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI vllm: affected >= 0.7.0, < 0.9.0; fixed in 0.9.0

## Suggested inspection (read-only)
- `python -m pip show vllm`: 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 vllm.
- 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-c65p-x677-fgj6 (OSV record GHSA-c65p-x677-fgj6 lists affected ranges: PyPI vllm >=0.7.0 <0.9.0 (fixed))
- Verified: https://github.com/advisories/GHSA-c65p-x677-fgj6 (GitHub-reviewed advisory GHSA-c65p-x677-fgj6 lists affected ranges: PyPI vllm >=0.7.0 <0.9.0)

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