CVE-2026-54236: vLLM: incomplete CVE-2026-22778 fix leaks PIL repr addresses via Anthropic router
vllm-project · vllm
Affected: vllm-project · Exploitation: check available, not yet exploited
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 61% of scored CVEs
DescriptionCVE.org
vLLM is an inference and serving engine for large language models (LLMs). Prior to 0.23.1rc0, the fix for CVE-2026-22778, which introduced a sanitize_message helper that strips object-repr memory addresses from error messages before they reach the client, is incomplete: several response paths echo str(exc) directly to clients without calling sanitize_message. The unsanitized sites include the Anthropic API router in vllm/entrypoints/anthropic/api_router.py (the POST /v1/messages and POST /v1/messages/count_tokens handlers), the Server-Sent Events streaming converter in vllm/entrypoints/anthropic/serving.py, and the realtime speech-to-text WebSocket in vllm/entrypoints/speech_to_text/realtime/connection.py. These paths catch the exception inside the route coroutine and construct the JSONResponse themselves, bypassing the sanitizing global FastAPI exception handler, and WebSocket frames do not traverse that handler chain at all. Using the same primitive as the parent issue, an unauthenticated attacker can send malformed image bytes through the Anthropic Messages API image content parts so that PIL.Image.open raises an UnidentifiedImageError whose message contains the BytesIO object repr, leaking the heap memory address verbatim in the error.message field of the response body. This vulnerability is fixed in 0.23.1rc0.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- vllm-project · vllm< 0.23.1rc0
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Check available, not yet exploited. A public nuclei template can confirm it on a system you are authorised to test.
- CISA KEV
- Not listed
- Public check
- vLLM <= 0.23.0 - Anthropic Router Heap Address Information Leak · nuclei template in projectdiscovery/nuclei-templates
- Vendor
- vllm-project
- Published
- June 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-54236 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.