CVE-2026-33942: Saloon is a PHP library that gives users tools to build API integrations and SDKs

Q: How do I fix CVE-2026-33942?

saloon: upgrade to 4.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-33942 being exploited?

CVE-2026-33942 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-33942 affect?

CVE-2026-33942 affects saloon. Severity is critical (CVSS 9.8). 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_

Q: How urgent is CVE-2026-33942?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-33942 is a critical-severity flaw (CVSS 9.8) affecting saloon. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 instan

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-03-26
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: saloon

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-26 01:16 UTCPublished CVE record published
2026-06-17 10:38 UTCUpdated Record last modified

saloon saloon UPGRADE

Affected: < 4.0.0

Fixed in: 4.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy saloon || rpm -q saloon || saloon --version

2. UPGRADE to 4.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade saloon

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade saloon

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33942?

saloon: upgrade to 4.0.0. Exact commands for each OS are on this page.

Is CVE-2026-33942 being exploited?

CVE-2026-33942 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33942 affect?

CVE-2026-33942 affects saloon. Severity is critical (CVSS 9.8). 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_

How urgent is CVE-2026-33942?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

Related CVEs

CVE-2026-33183 CRITICAL 9.1 UPGRADE Saloon is a PHP library that gives users tools to build API integrations and SDKs
CVE-2026-33182 HIGH 7.5 UPGRADE Saloon is a PHP library that gives users tools to build API integrations and SDKs

References

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