CVE-2026-27838: wger: IDOR via user-unscoped cache keys on routine API actions exposes workout data

Severity: low (CVSS 3.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-02-26 · updated 2026-06-17
Weakness: CWE-639

Description

wger is a free, open-source workout and fitness manager. Five routine detail action endpoints check a cache before calling `self.get_object()`. In versions up to and including 2.4, ache keys are scoped only by `pk` — no user ID is included. When a victim has previously accessed their routine via the API, an attacker can retrieve the cached response for the same PK without any ownership check. Commit e964328784e2ee2830a1991d69fadbce86ac9fbf contains a patch for the issue.

Affected products

wger-project wger: through 2.4

References

https://github.com/wger-project/wger/commit/e964328784e2ee2830a1991d69fadbce86ac9fbf
https://github.com/wger-project/wger/security/advisories/GHSA-42cr-w2gr-m54q

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