How severe is CVE-2026-33942?

CVE-2026-33942 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-33942 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33942?

CVE-2026-33942 affects Saloon. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33942?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-33942 have an EU (EUVD) identifier?

Yes. CVE-2026-33942 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16070.

When was CVE-2026-33942 published?

CVE-2026-33942 was published on 2026-03-26 and last updated on 2026-06-17.

CVE-2026-33942

CVE-2026-33942 is a critical-severity vulnerability in Saloon with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 8.1
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16070
Weakness: CWE-502
Affected product: Saloon
Published: 2026-03-26
Last modified: 2026-06-17

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.

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 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-33942 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33942?: CVE-2026-33942 affects Saloon. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33942?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-33942 have an EU (EUVD) identifier?: Yes. CVE-2026-33942 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16070.
When was CVE-2026-33942 published?: CVE-2026-33942 was published on 2026-03-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:saloon:saloon:*:*:*:*:*:*:*:*

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