8.1
HIGH CVSS 4.0
CVE-2026-33942
Saloon has insecure deserialization in AccessTokenAuthenticator (object injection / RCE)
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.

INFO

Published Date :

March 26, 2026, 1:16 a.m.

Last Modified :

March 26, 2026, 1:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-33942 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH [email protected]
Solution
Update Saloon library to version 4.0.0 or later to fix object injection vulnerability.
  • Update Saloon to version 4.0.0 or higher.
  • Manually manage authenticator storage and resolution.
  • Review and sanitize all user-supplied serialized data.
  • Remove usage of PHP unserialize() with user input.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-33942.

URL Resource
https://docs.saloon.dev/upgrade/upgrading-from-v3-to-v4
https://github.com/saloonphp/saloon/security/advisories/GHSA-rf88-776r-rcq9
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-33942 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-33942 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-33942 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-33942 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 26, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-502
    Added Reference https://docs.saloon.dev/upgrade/upgrading-from-v3-to-v4
    Added Reference https://github.com/saloonphp/saloon/security/advisories/GHSA-rf88-776r-rcq9
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.