How severe is CVE-2025-48951?

No CVSS score has been assigned to CVE-2025-48951 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-48951?

CVE-2025-48951 affects the following packages: auth0/auth0-php (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2025-48951?

Update auth0/auth0-php to 8.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-48951 is resolved across your whole dependency graph.

How do I detect CVE-2025-48951 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for auth0/auth0-php, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-48951 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2025-48951 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-48951 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-48951?

CVE-2025-48951 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 55th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-48951?

CVE-2025-48951 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2025-48951 published, and has it been updated?

CVE-2025-48951 was published on June 3, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2025-48951 — auth0-php

Fix: auth0/auth0-PHP@04b1f5d

CVE-2025-48951 is a Deserialization of Untrusted Data vulnerability in auth0/auth0-php. A fix is available for auth0/auth0-php — see the affected versions and patch details below.

Auth0-PHP SDK Deserialization of Untrusted Data vulnerability

Also known asGHSA-v9m8-9xxp-q492

Published

Jun 3, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-48951.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs55th percentile — riskier than 55% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐘auth0/auth0-php

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Overview The Auth0 PHP SDK contains a vulnerability due to insecure deserialization of cookie data. If exploited, since SDKs process cookie content without prior authentication, a threat actor could send a specially crafted cookie containing malicious serialized data.

Am I Affected? You are affected by this vulnerability if you meet the following preconditions:

Applications using the Auth0-PHP SDK, versions between 8.0.0-BETA3 to 8.3.0.
Applications using the following SDKs that rely on the Auth0-PHP SDK versions between 8.0.0-BETA3 to 8.3.0: a. Auth0/symfony, b. Auth0/laravel-auth0, c. Auth0/wordpress.

Fix Upgrade Auth0/Auth0-PHP to 8.3.1.

Acknowledgement Okta would like to thank Andreas Forsblom for discovering this vulnerability.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`auth0/auth0-php`	≥ 8.0.0-BETA3&&< 8.3.1	8.3.1`composer require auth0/auth0-php:^8.3.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for auth0/auth0-php, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update auth0/auth0-php to 8.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-48951 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Frequently Asked Questions

**Overview** The Auth0 PHP SDK contains a vulnerability due to insecure deserialization of cookie data. If exploited, since SDKs process cookie content without prior authentication, a threat actor could send a specially crafted cookie containing malicious serialized data. **Am I Affected?** You are affected by this vulnerability if you meet the following preconditions: 1. Applications using the Auth0-PHP SDK, versions between 8.0.0-BETA3 to 8.3.0. 2. Applications using the following SDKs that rely on the Auth0-PHP SDK versions between 8.0.0-BETA3 to 8.3.0: a. Auth0/symfony, b. Auth0

O3 Security · Impact-Aware SCA

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