GHSA-RF88-776R-RCQ9
Vulnerability from github – Published: 2026-03-27 18:33 – Updated: 2026-03-27 18:33Impact
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.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "saloonphp/saloon"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.0.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33942"
],
"database_specific": {
"cwe_ids": [
"CWE-502"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-27T18:33:43Z",
"nvd_published_at": "2026-03-26T01:16:28Z",
"severity": "HIGH"
},
"details": "### Impact\nUsers of the OAuth2 utilities in Saloon, specifically the `AccessTokenAuthenticator` class.\n\n### Patches\nUpgrade to Saloon v4+\n\nUpgrade guide: https://docs.saloon.dev/upgrade/upgrading-from-v3-to-v4\n\n### Description\nThe Saloon PHP library used PHP\u0027s unserialize() in AccessTokenAuthenticator::unserialize() to restore OAuth token state from cache or storage, with allowed_classes =\u003e 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.\n\n### Credits\nSaloon thanks @HuajiHD for finding the issue and recommending solutions and @jonpurvis for applying the fix.",
"id": "GHSA-rf88-776r-rcq9",
"modified": "2026-03-27T18:33:43Z",
"published": "2026-03-27T18:33:43Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/saloonphp/saloon/security/advisories/GHSA-rf88-776r-rcq9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33942"
},
{
"type": "WEB",
"url": "https://docs.saloon.dev/upgrade/upgrading-from-v3-to-v4"
},
{
"type": "PACKAGE",
"url": "https://github.com/saloonphp/saloon"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "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",
"type": "CVSS_V4"
}
],
"summary": "Saloon has insecure deserialization in AccessTokenAuthenticator"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.