CVE-2026-34236: Auth0-PHP is a PHP SDK for Auth0 Authentication and Management APIs

Routine

HIGH 8.2UPGRADE

CVE-2026-34236 is a high-severity flaw (CVSS 8.2) affecting auth0-php. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Auth0-PHP is a PHP SDK for Auth0 Authentication and Management APIs. From version 8.0.0 to before version 8.19.0, in applications built with the Auth0 PHP SDK, cookies are encrypted with insufficient entropy, which may result in threat actors brute-forcing the encryption key and forging session cookies. This issue has been patched in version 8.19.0.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 87%)
CISA exploited list	No
Weakness	CWE-331
Published	2026-04-01
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: auth0

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-01 18:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

auth0 auth0-php UPGRADE

Affected: >= 8.0.0 and < 8.19.0

Fixed in: 8.19.0

Safe to downgrade to: a release before 8.0.0

1. Check installed version

apt-cache policy auth0-php || rpm -q auth0-php || auth0-php --version

2. UPGRADE to 8.19.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade auth0-php

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade auth0-php

Note

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

3. If no update is available yet, DOWNGRADE to a release before 8.0.0 (Debian / Ubuntu)

apt-cache madison auth0-php sudo apt install auth0-php=<VERSION_BEFORE_8.0.0> sudo apt-mark hold auth0-php

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list auth0-php sudo dnf downgrade auth0-php-<VERSION_BEFORE_8.0.0> sudo dnf versionlock add auth0-php

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-34236?

auth0-php: upgrade to 8.19.0. Exact commands for each OS are on this page.

Is CVE-2026-34236 being exploited?

CVE-2026-34236 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-2026-34236 affect?

CVE-2026-34236 affects auth0-php. Severity is high (CVSS 8.2). Auth0-PHP is a PHP SDK for Auth0 Authentication and Management APIs. From version 8.0.0 to before version 8.19.0, in applications built with the Auth0 PHP SDK, cookies are encrypted with insufficient entropy, which may result in threat acto

How urgent is CVE-2026-34236?

Priority 32/100. High severity

Software pages

PHP vulnerabilities · Auth0 vulnerabilities

References

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