CVE-2025-21617
Guzzle OAuth Subscriber has insufficient nonce entropy
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Guzzle OAuth Subscriber has insufficient nonce entropy
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.
- Record
CVE-2025-21617- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-338
- Updated
- 2026-11-02
EUVDEUVD-2025-0003
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.
- Record
EUVD-2025-0003- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-237r-r8m4-4q88
Guzzle OAuth Subscriber has insufficient nonce entropy
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.
- Record
GHSA-237r-r8m4-4q88- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-338
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-21617- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-338
- Updated
- 2026-11-02
OSV
Guzzle OAuth Subscriber has insufficient nonce entropy
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.
- Record
CVE-2025-21617- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-338
- Updated
- 2026-11-02
OSVGHSA-237r-r8m4-4q88
Guzzle OAuth Subscriber has insufficient nonce entropy
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.
- Record
GHSA-237r-r8m4-4q88- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-338
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
guzzlehttp/oauth-subscriberPackagist |
before 0.8.1 | 0.8.1 |
guzzlehttp/oauth-subscriberPackagist |
before 0.8.1, plus listed versions 0.1.00.1.10.1.20.2.00.3.0 Show 5 moreShow less0.4.00.5.00.6.00.7.00.8.0 |
0.8.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-21617 is a medium vulnerability (CVSS 6.3) in Guzzle Oauth-subscriber, published January 6, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.48%, the 41st percentile. Fixed in guzzlehttp/oauth-subscriber 0.8.1.
References
github.com/guzzle/oauth-subscriber/security/advisories/GHSA-237r-r8m4-4q88
nvd.nist.gov/vuln/detail/CVE-2025-21617