pyLoad: Authentication bypass in API key validation (check_apikey cache)
Affects pyLoad 0.5.0b3 builds before 0.5.0b3.dev101, where a cached API-key check can accept a forged key for five minutes. Fixed in 0.5.0b3.dev101.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 0.5.0b3.dev101
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.5.0b3.dev101.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 25/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
pyLoad, a Python-based download manager, contains an authentication bypass in its API key validation that lets a remote attacker reach the API without logging in. By guessing a small sequential key identifier while a legitimate key is cached, an attacker can gain the cached key owner's permissions for about five minutes.
Read the original description
pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev101, Api.check_apikey caches successful validation in self._apikey_cache using only the attacker-controlled key_id. After a legitimate key populates the cache, a forged API key with the same key_id reaches the cache-hit path without comparing apikey[-43:] to the stored hash through hmac.compare_digest. Key identifiers are small sequential integers, so an unauthenticated remote attacker can enumerate an active identifier and inherit the cached key owner's permissions during the 300-second cache lifetime. This issue is fixed in version 0.5.0b3.dev101.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed, reachable over the network without a login · Unknown: Advisories don't say whether default setups are affected
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.1/10CVSS 8.1
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 0.5.0b3.dev101.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- pyload pyload
fixed in 0.5.0b3.dev101
Evidence 2
- Advisory
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123816
Is CVE-2026-123816 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The API-key check caches results for 300 seconds by default, and a forged API key with a valid key_id is accepted during that window. This lets a remote attacker authenticate and act with the associated user's permissions.Source: github.com
Which versions are affected by CVE-2026-123816?
pyload: before 0.5.0b3.dev101.Source: cve.now feed data
Am I affected, and how do I check?
Affected versions are pyLoad 0.5.0b3 before 0.5.0b3.dev101. To check, compare the installed pyLoad version against that range; the issue involves the default 300-second API-key cache used by normal API requests when no ttl is given.Source: github.com
How do I fix CVE-2026-123816?
Upgrade pyLoad to 0.5.0b3.dev101 or later, which is the patched version named in the advisory.Source: github.com