How severe is GHSA-237r-r8m4-4q88?

No CVSS score has been assigned to GHSA-237r-r8m4-4q88 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-237r-r8m4-4q88?

GHSA-237r-r8m4-4q88 affects the following packages: guzzlehttp/oauth-subscriber (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-237r-r8m4-4q88?

Update guzzlehttp/oauth-subscriber to 0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-237r-r8m4-4q88 is resolved across your whole dependency graph.

How do I detect GHSA-237r-r8m4-4q88 in my Packagist dependencies?

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

How do I mitigate GHSA-237r-r8m4-4q88 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-237r-r8m4-4q88 actively exploited in the wild?

No public exploit code has been indexed for GHSA-237r-r8m4-4q88 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 GHSA-237r-r8m4-4q88?

GHSA-237r-r8m4-4q88 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 42th 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 GHSA-237r-r8m4-4q88?

GHSA-237r-r8m4-4q88 is classified as CWE-338 (CWE-338). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-237r-r8m4-4q88 published, and has it been updated?

GHSA-237r-r8m4-4q88 was published on January 6, 2025 and was last updated on July 15, 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

Guzzle OAuth Subscriber has insufficient nonce entropyGHSA-237r-r8m4-4q88

Fix: guzzle/oauth-subscriber@92b619b

GHSA-237r-r8m4-4q88 is a CWE-338 vulnerability in guzzlehttp/oauth-subscriber. A fix is available for guzzlehttp/oauth-subscriber — see the affected versions and patch details below.

Also known asCVE-2025-21617

Published

Jan 6, 2025

Updated

Jul 15, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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 GHSA-237r-r8m4-4q88.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs42th percentile — riskier than 42% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg affected

🐘guzzlehttp/oauth-subscriber

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

Impact

Nonce generation does not use sufficient entropy nor a cryptographically secure pseudorandom source (https://github.com/guzzle/oauth-subscriber/blob/0.8.0/src/Oauth1.php#L192). This can leave servers vulnerable to replay attacks when TLS is not used.

Patches

Upgrade to version 0.8.1 or higher.

Workarounds

No.

References

Issue is similar to https://nvd.nist.gov/vuln/detail/CVE-2025-22376.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`guzzlehttp/oauth-subscriber`	all versions	0.8.1`composer require guzzlehttp/oauth-subscriber:^0.8.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for guzzlehttp/oauth-subscriber, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update guzzlehttp/oauth-subscriber to 0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-237r-r8m4-4q88 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Impact Nonce generation does not use sufficient entropy nor a cryptographically secure pseudorandom source (https://github.com/guzzle/oauth-subscriber/blob/0.8.0/src/Oauth1.php#L192). This can leave servers vulnerable to replay attacks when TLS is not used. ### Patches Upgrade to version 0.8.1 or higher. ### Workarounds No. ### References Issue is similar to https://nvd.nist.gov/vuln/detail/CVE-2025-22376.

O3 Security · Impact-Aware SCA

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