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.
https://www.vulncheck.com/advisories/uber-kraken-through-0.1.29-path-traversal-via-tag-parameter
https://github.com/uber/kraken/issues/645
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/lib/backend/namepath/pather.go#L78-L84
https://github.com/uber/kraken/blob/v0.1.27/build-index/tagserver/server.go#L128-L129
Published: 2026-09-16
Updated: 2026-09-21
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N
Severity: High
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: High
Base Score: 8.7
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
Severity: High
EPSS: 0.00505