Vulnerability · Published Mar 26, 2026 · Assigned by GitHub_M
CVE-2026-33942Saloon has insecure deserialization in AccessTokenAuthenticator (object injection / RCE)
High 8.1
In plain English
A high-severity unsafe deserialization in saloon from saloonphp. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Saloon is a PHP library that gives users tools to build API integrations and SDKs. Versions prior to 4.0.0 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 in version 4.0.0 removes PHP serialization from the AccessTokenAuthenticator class requiring users to store and resolve the authenticator manually.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | saloonphp/saloon | 4.0.0 | GHSA-rf88-776r-rcq9 |
Affected products (as reported)
Weakness: CWE-502 · Vector: 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
References
- https://github.com/saloonphp/saloon/security/advisories/GHSA-rf88-776r-rcq9 x_refsource_CONFIRM
- https://docs.saloon.dev/upgrade/upgrading-from-v3-to-v4 x_refsource_MISC