How severe is GHSA-42cr-w2gr-m54q?

GHSA-42cr-w2gr-m54q has a CVSS score of 3.1/10, rated LOW. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-42cr-w2gr-m54q?

GHSA-42cr-w2gr-m54q affects the following packages: wger (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-42cr-w2gr-m54q?

No patched version of wger has shipped for GHSA-42cr-w2gr-m54q yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect GHSA-42cr-w2gr-m54q in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wger. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-42cr-w2gr-m54q if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-42cr-w2gr-m54q?

O3 pinpoints whether GHSA-42cr-w2gr-m54q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-42cr-w2gr-m54q actively exploited in the wild?

No public exploit code has been indexed for GHSA-42cr-w2gr-m54q yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-42cr-w2gr-m54q?

GHSA-42cr-w2gr-m54q has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 15th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-42cr-w2gr-m54q?

GHSA-42cr-w2gr-m54q is classified as CWE-639 (CWE-639). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-42cr-w2gr-m54q published, and has it been updated?

GHSA-42cr-w2gr-m54q was published on February 26, 2026 and was last updated on April 15, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

GHSA-42cr-w2gr-m54q

LOW

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

Also known asCVE-2026-27838

Published

Feb 26, 2026

Updated

Apr 15, 2026

Affected

1 pkg

Patched

None yet

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk15th percentile+0.21%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐍wger

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Five routine detail action endpoints check a cache before calling self.get_object(). Cache 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.

Details

wger/manager/api/views.py — five actions follow this pattern (lines 134–201):

@action(detail=True)
def date_sequence_display_mode(self, request, pk=None):
    cache_key = make_routine_api_date_sequence_display_cache_key(pk)
    cached = cache.get(cache_key)
    if cached:
        return Response(cached)   # returned WITHOUT calling self.get_object()
    # only reaches ownership check on cache miss
    routine = self.get_object()
    ...

Cache key construction in wger/utils/cache.py:89–106:

def make_routine_api_date_sequence_display_cache_key(routine_id):
    return f"routine-api-date-sequence-display-{routine_id}"
    # No user ID in key

Cache TTL: 1 month (4 * 604800 seconds, settings_global.py:461).

Affected endpoints:

GET /api/v2/routine/{pk}/date-sequence-display/
GET /api/v2/routine/{pk}/date-sequence-gym/
GET /api/v2/routine/{pk}/structure/
GET /api/v2/routine/{pk}/logs/
GET /api/v2/routine/{pk}/stats/

PoC

1. Victim (user A) visits GET /api/v2/routine/5/structure/ → response cached under key "routine-api-structure-5"
2. Attacker (user B) visits GET /api/v2/routine/5/structure/ → cache hit → returns user A's routine structure without any ownership check

Requires the victim to have previously accessed the endpoint (cache must be populated). Once populated, the cache entry is valid for 1 month.

Impact

An attacker with a registered account can retrieve another user's routine details — workout day sequences, exercise structure, training logs, and statistics — from cache without ownership verification.

Fix: Include the user ID in the cache key:

def make_routine_api_date_sequence_display_cache_key(routine_id, user_id):
    return f"routine-api-date-sequence-display-{user_id}-{routine_id}"

Or move self.get_object() before the cache lookup so ownership is always verified first.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`wger`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wger. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of wger has shipped for GHSA-42cr-w2gr-m54q yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-42cr-w2gr-m54q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-42cr-w2gr-m54q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary Five routine detail action endpoints check a cache before calling `self.get_object()`. Cache 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. ### Details `wger/manager/api/views.py` — five actions follow this pattern (lines 134–201): ```python @action(detail=True) def date_sequence_display_mode(self, request, pk=None): cache_key = make_routine_api_date_sequence_display_cache_key(pk) cached = cache.get(cache_key)

O3 Security · Impact-Aware SCA

Is GHSA-42cr-w2gr-m54q in your dependencies?

O3 detects GHSA-42cr-w2gr-m54q across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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