What’s Vulnerable › Vulnerabilities

CVE-2025-21617: Guzzle OAuth Subscriber has insufficient nonce entropy

• Severity: medium (CVSS 6.3 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-01-06 · updated 2026-06-17
• Weakness: CWE-338

Description

Guzzle OAuth Subscriber signs Guzzle requests using OAuth 1.0. Prior to 0.8.1, Nonce generation does not use sufficient entropy nor a cryptographically secure pseudorandom source. This can leave servers vulnerable to replay attacks when TLS is not used. This vulnerability is fixed in 0.8.1.

Affected products

• guzzle oauth-subscriber: before 0.8.1

References

• https://github.com/guzzle/oauth-subscriber/blob/0.8.0/src/Oauth1.php#L192
• https://github.com/guzzle/oauth-subscriber/commit/92b619b03bd21396e51c62e6bce83467d2ce8f53
• https://github.com/guzzle/oauth-subscriber/releases/tag/0.8.1
• https://github.com/guzzle/oauth-subscriber/security/advisories/GHSA-237r-r8m4-4q88

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