dbcve.org
SaloonApplication

CVE-2026-33942

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-26
Fix available
A fix is available. Upgrade to 4.0.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Saloon PHP library versions before 4.0.0 have a critical object injection vulnerability in AccessTokenAuthenticator::unserialize() which uses PHP's unserialize() with allowed_classes => true. An attacker who can control serialized token data (e.g., via cache file overwrite or injection) can supply malicious 'gadget' objects that execute __wakeup, __destruct, or other magic methods upon deserialization, enabling RCE when chained with common dependencies like Monolog.

MitigationUpgrade to Saloon version 4.0.0 or later which removes PHP serialization from the AccessTokenAuthenticator class. Alternatively, ensure cache/storage files containing serialized tokens are protected from unauthorized modification and implement integrity validation on deserialized data.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SaloonApplication
Affected:< 4.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Saloon library version
    Run 'composer show saloon/saloon' or check your composer.lock file for the installed version of the saloon/saloon package
    Affected if The installed version is below 4.0.0
  2. Locate AccessTokenAuthenticator class
    Search for the AccessTokenAuthenticator class file within the Saloon library installation directory and inspect its contents for unserialize() calls
    Affected if The file contains an unserialize() call with allowed_classes parameter set to true or not restricted
  3. Identify serialized token storage
    Search project codebase for cache files, storage directories, or configuration where AccessTokenAuthenticator serializes token data
    Affected if Serialized token objects are stored in files or storage that could be modified by an attacker
  4. Check for gadget chain dependencies
    Run 'composer show' and check if Monolog, Symfony components, or other common PHP unserialize gadget libraries are installed alongside Saloon
    Affected if Libraries known to contain gadget chains for PHP object injection are present in the same PHP environment

A user is affected if Saloon version is below 4.0.0, the AccessTokenAuthenticator uses unsafe unserialize, and an attacker can control or inject serialized token data.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.0.0 or later
Fixed in 4.0.0
Interim mitigation

Upgrade to Saloon version 4.0.0 or later which removes PHP serialization from the AccessTokenAuthenticator class. Alternatively, ensure cache/storage files containing serialized tokens are protected from unauthorized modification and implement integrity validation on deserialized data.

Recommended fix High confidence

Saloon 4.0.0

  1. Upgrade the Saloon PHP library to version 4.0.0 or later via Composer: `composer require saloonphp/saloon:^4.0`
  2. After upgrading, review any custom AccessTokenAuthenticator implementations as the class no longer supports PHP serialization
  3. Update your token storage mechanism to store raw token data (access_token, refresh_token, expires_at) instead of serialized objects
  4. Implement the manual authenticator resolution logic as required by version 4.0.0 - the AccessTokenAuthenticator now expects you to handle token restoration from your own storage
Caveat Version 4.0.0 removes PHP serialization from AccessTokenAuthenticator - users must manually store and resolve authenticators; existing cached serialized tokens will become invalid and require migration

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Saloon Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-33942 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33942 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data