Net::OAuth versions before 0.33 for Perl check HMAC-SHA1, HMAC-SHA256 and PLAINTEXT signatures with a non-constant-time comparison in verify. Each of the three compares the signature carried in the message against the locally computed one with the eq operator, which returns as soon as the two strings differ. The time taken to reject a signature varies with the length of the matching prefix. RSA-SHA1 is not affected, as it verifies through the RSA key object rather than by comparing strings. A client that can submit messages and time the replies may recover a valid signature one byte at a time rather than searching the whole signature space. Under PLAINTEXT the value compared against is the signature key itself, so the search recovers consumer_secret and token_secret.
History

Wed, 19 Aug 2026 07:30:00 +0000

Type Values Removed Values Added
Description Net::OAuth versions before 0.33 for Perl check HMAC-SHA1, HMAC-SHA256 and PLAINTEXT signatures with a non-constant-time comparison in verify. Each of the three compares the signature carried in the message against the locally computed one with the eq operator, which returns as soon as the two strings differ. The time taken to reject a signature varies with the length of the matching prefix. RSA-SHA1 is not affected, as it verifies through the RSA key object rather than by comparing strings. A client that can submit messages and time the replies may recover a valid signature one byte at a time rather than searching the whole signature space. Under PLAINTEXT the value compared against is the signature key itself, so the search recovers consumer_secret and token_secret.
Title Net::OAuth versions before 0.33 for Perl check HMAC-SHA1, HMAC-SHA256 and PLAINTEXT signatures with a non-constant-time comparison in verify
Weaknesses CWE-208
References

cve-icon MITRE

Status: PUBLISHED

Assigner: CPANSec

Published:

Updated: 2026-08-19T07:20:44.880Z

Reserved: 2026-08-17T22:30:33.360Z

Link: CVE-2026-75589

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-19T08:17:13.970

Modified: 2026-08-19T08:17:13.970

Link: CVE-2026-75589

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.