CVE-2026-33942

HIGHCVSS 8.1/10EPSS 0.62%

Last modified

CVE-2026-33942 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. 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. EPSS estimates a 0.62% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS 4.0
8.1/10

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/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

EPSS Probability
0.62%

45.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
SaloonSaloon< 4.0.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-33942?
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.
How severe is CVE-2026-33942?
CVE-2026-33942 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 0.62% probability of exploitation in the next 30 days.
How do I fix CVE-2026-33942?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-33942?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST