CVE-2025-47275: Brute Force Authentication Tags of CookieStore Sessions in Auth0-PHP SDK

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.5%, percentile 45: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 45% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes auth0/auth0-php (Composer (PHP)) >= 8.0.0-BETA1, < 8.14.0, fixed in 8.14.0. Check your lockfile, including transitive dependencies.

What it is

Auth0-PHP provides the PHP SDK for Auth0 Authentication and Management APIs. Starting in version 8.0.0-BETA1 and prior to version 8.14.0, session cookies of applications using the Auth0-PHP SDK configured with CookieStore have authentication tags that can be brute forced, which may result in unauthorized access. Certain pre-conditions are required to be vulnerable to this issue: Applications using the Auth0-PHP SDK, or the Auth0/symfony, Auth0/laravel-auth0, and Auth0/wordpress SDKs that rely on the Auth0-PHP SDK; and session storage configured with CookieStore. Upgrade Auth0/Auth0-PHP to v8.14.0 to receive a patch. As an additional precautionary measure, rotating cookie encryption keys is recommended. Note that once updated, any previous session cookies will be rejected.

From the GitHub advisory

Overview Session cookies of applications using the Auth0-PHP SDK configured with CookieStore have authentication tags that can be brute forced, which may result in unauthorized access.

Am I Affected? You are affected by this vulnerability if you meet the following pre-conditions: 1. Applications using the Auth0-PHP SDK, or the following SDKs that rely on the Auth0-PHP SDK: a. Auth0/symfony, b. Auth0/laravel-auth0, c. Auth0/wordpress, 2. Session storage configured with CookieStore.

Fix Upgrade Auth0/Auth0-PHP to v8.14.0. As an additional precautionary measure, we recommend rotating your cookie encryption keys. Note that once updated, any previous session cookies will be rejected.

Acknowledgement Okta would like to thank Félix Charette for discovering this vulnerability.

Weakness type: CWE-287.

Product: auth0/auth0-php (Composer (PHP)) · Assigned by: GitHub_M · Published: 2025-05-15

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.54% probability of exploitation activity in the next 30 days; percentile 45.

Timeline

• 2025-05-15 — CVE record published by GitHub_M
• 2025-05-16 — GitHub-reviewed advisory GHSA-g98g-r7gf-2r25 published (critical)
• 2025-05-22 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-g98g-r7gf-2r25 github.com
2. CVE.org record CVE-2025-47275 cve.org
3. NVD entry CVE-2025-47275 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. github.com github.com
6. github.com github.com

Critical Composer (PHP) advisories · Today’s Security Digest