Summary
pyLoad has an authentication bypass in API key validation (check_apikey cache)
The API-key cache in check_apikey() allows an attacker to authenticate with a forged API key as long as the legitimate key for the same key_id has been used recently.
On a cache hit, the API key secret is never verified, resulting in a complete authentication bypass during the cache lifetime.
Affected Components
src/pyload/core/api/init.pyApi.check_apikey()
src/pyload/core/database/apikey_database.pycheck_apikey()_check_key()
The cache is used by normal API requests through:
src/pyload/webui/app/helpers.py
which calls:
api.check_apikey(api_key)
without providing a ttl, meaning the default 300-second cache is always enabled.
Root Cause
Successful API key validations are cached in:
self._apikey_cache
using the following structure:
{
key_id: (timestamp, cached_data)
}
The cache key is based only on key_id, and that value is parsed directly from the user-supplied API key rather than being obtained from a trusted lookup.
When a cache hit occurs within the TTL, check_apikey() returns:
{
"success": True,
"data": cached_data
}
after checking only:
expires_at
At no point on this execution path is the supplied secret:
apikey[-43:]
compared against the stored key hash.
The actual secret verification exists only in:
_check_key()
which correctly uses:
hmac.compare_digest()
However, this function is only reached on a cache miss through the database layer's check_apikey() implementation.
Furthermore, the cached object cannot be used for verification because it intentionally does not include the stored key hash.
The cached record contains only:
iduser_idnamecreated_atexpires_atlast_used
Since key_hash is absent, the cache lacks the information required to validate the presented secret.
As a result, once a legitimate request populates the cache, every subsequent request using the same key_id within the 300-second cache window is accepted without validating the secret.
Estimated CVSS v3.1
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
(AC:H only because successful exploitation depends on the cache already containing an entry.)
Reproduction
1. Create an administrator account.
2. Generate an API key.
Example:
pl_11<43-character-secret>
where:
key_id = 1
3. Send a legitimate authenticated request.
curl \
-H "X-API-Key: pl_11<real-43-char-secret>" \
http://127.0.0.1:8000/api/status
Expected response:
HTTP/1.1 200 OK
4. Within 300 seconds, send the same request using a forged API key.
curl \
-H "X-API-Key: pl_11xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" \
http://127.0.0.1:8000/api/status
Observed response:
HTTP/1.1 200 OK
The request succeeds even though the API key secret is entirely incorrect.
Control Test
If the forged API key is sent before any legitimate request has populated the cache, the server correctly returns:
HTTP/1.1 401 Unauthorized
The only difference between the failing and succeeding forged request is whether the cache already contains an entry for that key_id.
This isolates the vulnerability specifically to the cache-hit path.
Impact
key_id values are small sequential integers assigned when API keys are created (1, 2, 3, ...), making them trivial to enumerate.
The API key format is also publicly reconstructable from the source code.
An attacker therefore does not need to know any valid API key secret.
They only need a key_id whose legitimate key has been used within the previous five minutes, which is likely on an actively used deployment.
During that cache window, a forged API key follows exactly the same authentication path as a legitimate key and inherits the associated user's permissions.
This results in a complete remote authentication bypass.
I would classify the issue as Critical severity.
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
GHSA-R44W-V6GF-X3P6 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.5.0b3.dev101); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Cache hits should never replace secret verification.
Possible approaches include:
Store a value derived from the complete API key (or its hash) in the cache and verify it using
hmac.compare_digest()on every cache hit before returning success.Alternatively, key the cache using a value derived from the entire API key secret (for example, a cryptographic hash of the complete API key) rather than using only
key_id.
Regardless of implementation, the security invariant should remain:
The API key secret must be validated on every authenticated request, regardless of whether the cache is hit or missed.
Frequently Asked Questions
- What is GHSA-R44W-V6GF-X3P6? GHSA-R44W-V6GF-X3P6 is a high-severity improper authentication vulnerability in pyload-ng (pip), affecting versions < 0.5.0b3.dev101. It is fixed in 0.5.0b3.dev101. The application does not adequately verify the identity of a user, device, or process before granting access.
- How severe is GHSA-R44W-V6GF-X3P6? GHSA-R44W-V6GF-X3P6 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of pyload-ng are affected by GHSA-R44W-V6GF-X3P6? pyload-ng (pip) versions < 0.5.0b3.dev101 is affected.
- Is there a fix for GHSA-R44W-V6GF-X3P6? Yes. GHSA-R44W-V6GF-X3P6 is fixed in 0.5.0b3.dev101. Upgrade to this version or later.
- Is GHSA-R44W-V6GF-X3P6 exploitable, and should I be worried? Whether GHSA-R44W-V6GF-X3P6 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-R44W-V6GF-X3P6 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-R44W-V6GF-X3P6? Upgrade
pyload-ngto 0.5.0b3.dev101 or later.