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CVE

CVE-2025-66506

Fulcio allocates excessive memory during token parsing
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CVE

CVE-2025-66506

Fulcio allocates excessive memory during token parsing

Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split) its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument), with a constant factor of about 16. This vulnerability is fixed in 1.8.3.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
7.5
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66506.json, https://github.com/sigstore/fulcio/commit/765a0e57608b9ef390e1eeeea8595b9054c63a5a, https://github.com/sigstore/fulcio/security/advisories/GHSA-f83f-xpx7-ffpw, https://nvd.nist.gov/vuln/detail/CVE-2025-66506

Severity

7.5

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
7.5
EPSS Probability
0.00033%
EPSS Percentile
0.09079%
Introduced Version
0
Fix Available
3622f6e62cf74ff1477422a8c3aad4ca338ed047,0:1.10.0-1.amzn2.0.6,0:1.10.0-1.amzn2023.0.6

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