CWE-757Base

Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')

Incomplete in the CWE catalog · 33 CVEs mapped

33
CVEs mapped
6.5
Median CVSS
What it is

A protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties.

Recent examples
6.6cvss
CVE-2026-59293

CVE-2026-59293 - MEDIUM Severity Vulnerability

Unless the application explicitly raises smbMinVersion, the jCIFS client will negotiate down to SMB1/CIFS, which lacks mandatory signing/encryption and is vulnerable to NTLM relay and content-tampering MITM. Spring Integration 7.1.0 Spring Integration 7.0.0 - 7.0.5 Spring Integration 6.5.0 - 6.5.10 Spring Integration 6.4.0 - 6.4.12

MEDIUMno explanation yet
0%
epss
9.8cvss
CVE-2026-72889

CVE-2026-72889 - CRITICAL Severity Vulnerability

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.

CRITICALno explanation yet
0%
epss
9.8cvss
CVE-2026-72887

CVE-2026-72887 - CRITICAL Severity Vulnerability

Net::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_token. Passing a callback to the constructor selects OAuth 1.0a. get_request_token then revokes that choice when the request token response omits oauth_callback_confirmed, with no exception, no warning and no option to require 1.0a. The access token request is built from the OAuth 1.0 message class, which has no verifier parameter, so oauth_verifier is dropped from the request even when get_access_token was passed one. oauth_verifier is the binding that OAuth 1.0a added between the authorization step and the token exchange. An application that asked for 1.0a and gets 1.0 is open to OAuth 1.0 session fixation, where an attacker obtains a request token, has the victim authorize it, and then completes the exchange themselves, linking the victim's provider account to a session the attacker controls. No attacker action sets up the downgrade: a provider that does not confirm the callback is enough.

CRITICALno explanation yet
1%
epss
The record
Technical detail
CWE ID
CWE-757
Abstraction
Base
Structure
Simple
Status
Incomplete