CVE WatchAug 19, 2026

CVE-2026-72889

Net::OAuth versions before 0.33 for Perl allow the sender to choose the signature algorithm in verify. verify resolves the signature method

CVSS

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No CVSS

EPSS

0.1%

KEV

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Exploit Today

0-100

Published: Aug 19, 2026 · Last modified: Aug 19, 2026 · CWE-347 · CWE-757

EPSS · 30d

Not enough EPSS history yet.

Technical description

Net::OAuth versions before 0.33 for Perl allow the sender to choose the signature algorithm in verify. verify resolves the signature method class from the signature_method parameter of the incoming message. signature_method is required on every request, so the algorithm used to check a signature is chosen by whoever sent it, and nothing lets the verifying party pin the method instead. When a message names HMAC-SHA1 or HMAC-SHA256, the key is derived from consumer_secret and token_secret rather than from the key the provider deployed. A provider deployed on RSA-SHA1 holds only the consumer public key, and RFC 5849 does not use consumer_secret for that method, so the required parameter is filled with a placeholder. A client that names HMAC-SHA1 instead has its signature checked against that placeholder, so a guessable one is enough to forge requests for any consumer key and token.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-762347.5 HIG

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——5openssl_encrypt versions before 1.4.0 contain an authentication bypass vulnerability in pqc.py where AES-GCM decryption failures trigger fallback to unauthenticated AES-CTR mode. Attackers can modify ciphertext in transit to bypass integrity verification and perform bit-flipping attacks without detection.3d CVE-2026-748769.8 CRI

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