CVE-2026-33942
Saloon has insecure deserialization in AccessTokenAuthenticator
Description
### Impact Users of the OAuth2 utilities in Saloon, specifically the `AccessTokenAuthenticator` class. ### Patches Upgrade to Saloon v4+ Upgrade guide: https://docs.saloon.dev/upgrade/upgrading-from-v3-to-v4 ### Description The Saloon PHP library used PHP's unserialize() in AccessTokenAuthenticator::unserialize() to restore OAuth token state from cache or storage, with allowed_classes => true. An attacker who can control the serialized string (e.g. by overwriting a cached token file or via another injection) can supply a serialized "gadget" object. When unserialize() runs, PHP instantiates that object and runs its magic methods (__wakeup, __destruct, etc.), leading to object injection. In environments with common dependencies (e.g. Monolog), this can be chained to remote code execution (RCE). The fix removes PHP serialization from the AccessTokenAuthenticator class requiring users to store and resolve the authenticator manually. ### Credits Saloon thanks @HuajiHD for finding the issue and recommending solutions and @jonpurvis for applying the fix.
How to fix CVE-2026-33942
To remediate CVE-2026-33942, upgrade the affected package to a fixed version below.
- —upgrade to 4.0.0 or later
Is CVE-2026-33942 being exploited?
Low — EPSS is 0.6%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 4.0.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U |