How severe is CVE-2025-21617?

CVE-2025-21617 has a CVSS 4.0 base score of 6.3, rated medium severity.

Is CVE-2025-21617 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-21617?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-21617 have an EU (EUVD) identifier?

Yes. CVE-2025-21617 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-0003.

When was CVE-2025-21617 published?

CVE-2025-21617 was published on 2025-01-06 and last updated on 2026-06-17.

CVE-2025-21617

CVE-2025-21617 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-338.

Key facts

Severity: Medium (CVSS 4.0 base score 6.3)
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-0003
Weakness: CWE-338
Published: 2025-01-06
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-21617?: 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.
How severe is CVE-2025-21617?: CVE-2025-21617 has a CVSS 4.0 base score of 6.3, rated medium severity.
Is CVE-2025-21617 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-21617?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-21617 have an EU (EUVD) identifier?: Yes. CVE-2025-21617 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-0003.
When was CVE-2025-21617 published?: CVE-2025-21617 was published on 2025-01-06 and last updated on 2026-06-17.

References

Other CWE-338 vulnerabilities

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CVE-2026-3256 — Critical (CVSS 9.8): HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults…
CVE-2025-15604 — Critical (CVSS 9.8): Amon2 versions before 6.17 for Perl use an insecure random_string implementation for security functions. In versions…
CVE-2025-40926 — Critical (CVSS 9.8): Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default session…
CVE-2026-2439 — Critical (CVSS 9.8): Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id…
CVE-2025-15578 — Critical (CVSS 9.8): Maypole versions from 2.10 through 2.13 for Perl generates session ids insecurely. The session id is seeded with the…

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