CWE-837Base

Improper Enforcement of a Single, Unique Action

Incomplete in the CWE catalog · 17 CVEs mapped

17
CVEs mapped
5.3
Median CVSS
What it is

The product requires that an actor should only be able to perform an action once, or to have only one unique action, but the product does not enforce or improperly enforces this restriction.

Recent examples
5.3cvss
CVE-2026-45734

CVE-2026-45734 - MEDIUM Severity Vulnerability

MyBB is free and open source forum software. Prior to 1.8.40, the built-in CAPTCHA does not consistently enforce single-use semantics, allowing remote attackers to bypass CAPTCHA controls through challenge replay. The successful validation paths in contact.php, member.php?action=do_resendactivation, member.php?action=do_lostpw, member.php?action=do_emailuser, and sendthread.php?action=do_sendtofriend do not call captcha::invalidate_captcha() for the MyBB Default CAPTCHA selected by the captchaimage setting. A valid response can therefore be reused until a non-vulnerable endpoint invalidates it, an incorrect response is submitted, or the challenge expires. This issue is fixed in version 1.8.40.

MEDIUMno explanation yet
0%
epss
8.1cvss
CVE-2026-42609

Grav: Administrative Account Disruption and Privilege De-escalation via User Overwrite Logic

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, a business logic vulnerability in the Grav Admin Panel allows a low-privileged user (with only user creation permissions) to overwrite existing accounts, including the primary administrator. By creating a new user with a username that already exists, the system updates the existing account's metadata and permissions instead of rejecting the request. This leads to a Denial of Service (DoS) on administrative functions and Privilege De-escalation of the root account. This vulnerability is fixed in 2.0.0-beta.2.

HIGHno explanation yet
0%
epss
3.7cvss
CVE-2026-44601

Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a double close of a circuit, aka TROVE-2026-009

Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a double close of a circuit, aka TROVE-2026-009.

LOWno explanation yet
0%
epss
The record
Technical detail
CWE ID
CWE-837
Abstraction
Base
Structure
Simple
Status
Incomplete