openemr: Improper Restriction of Excessive Authentication Attempts
CVE-2026-126454 is a high-severity improper restriction of excessive authentication attempts vulnerability in openemr, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 8.5.0 as the first without the flaw, so updating openemr to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.41% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update openemr to 8.5.0 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.6 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.1 | High | CNA (vulncheck.com) |
Official description
OpenEMR before 8.5.0 lacks rate limiting or lockout on TOTP submission, allowing attackers with a valid password to brute-force the 6-digit MFA code. Attackers can script repeated POST requests to main_screen.php or the OAuth2 authorization flow with re-submitted hidden credentials to bypass two-factor authentication.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of Excessive Authentication Attempts
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
How developers prevent this class of flaw
- Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
More Improper Restriction of Excessive Authentication Attempts vulnerabilities (CWE-307)
Timeline
- CVE record published.
References
Other references
Other vulnerabilities in openemr
- 7.1 High severity
- 8.8 High severity
- 7.6 High severity
- 7.2 High severity
- 7.7 High severity
- 8.8 High severity
Recent Improper Restriction of Excessive Authentication Attempts vulnerabilities
- 8.1 High severity
- 7.4 High severity
- 7.4 High severity
- 7.4 High severity
- 7.4 High severity
- 7.4 High severity
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