CVE-2026-75589: high-severity vulnerability in Net-OAuth
Net::OAuth versions before 0.33 for Perl check HMAC-SHA1, HMAC-SHA256 and PLAINTEXT signatures with a non-constant-time comparison in verify
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products
Net-OAuthRelated CVEs — Net-OAuth
In the same product, most dangerous first.
CVE-2026-72887CRITICALNet::OAuth::Client versions before 0.32 for Perl allow the service provider to silently downgrade OAuth 1.0a to OAuth 1.0 in get_request_tokenEPSS 0.7%CVE-2026-72888MEDIUMNet::OAuth versions before 0.32 for Perl allow memory exhaustion via unbounded caching of failed module loads in smart_requireEPSS 0.5%CVE-2026-72889CRITICALNet::OAuth versions before 0.33 for Perl allow the sender to choose the signature algorithm in verifyEPSS 0.4%