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GHSA-rf88-776r-rcq9

HighCVSS 8.1 / 10
Published Mar 27, 2026·Last modified Mar 27, 2026
Affected Components(0)

No affected components available

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.

Risk Scores
Base Score
8.1

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
8.1

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.62%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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