CVE-2026-33667: opf openproject · Improper Restriction of Excessive Authentication Attempts
Affects opf openprojectSource CVE Database V5
Not known to be exploited · CVSS 7.4 High : upgrade to 17.3.0 soon.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 17.3.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 15 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade openproject and opf/openproject to 17.3.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| opfopenproject | Affected
| Fixed in
|
GitHubopf/openprojectpkg:github/opf/openprojectOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade OpenProject to version 17.3.0 or later, where this vulnerability has been fixed by implementing proper rate limiting and lockout mechanisms on 2FA OTP verification. Until upgrading, be aware that accounts with known passwords are vulnerable to 2FA bypass via brute force. Patch status is not explicitly stated in vendor advisory content but the fix is included in version 17.3.0.
Description
OpenProject is an open-source project management application. In versions prior to 17.3.0, 2FA OTP verification in the confirm_otp action of the two_factor_authentication module has no rate limiting, lockout mechanism, or failed-attempt tracking. The existing brute_force_block_after_failed_logins setting only counts password login failures and does not apply to the 2FA verification stage, and neither the fail_login nor stage_failure methods increment any counter, lock the account, or add any delay. With the default TOTP drift window of ±60 seconds allowing approximately 5 valid codes at any time, an attacker who knows a user's password can brute-force the 6-digit TOTP code at roughly 5-10 attempts per second with an expected completion time of approximately 11 hours. The same vulnerability applies to backup code verification. This effectively allows complete 2FA bypass for any account where the password is known. This issue has been fixed in version 17.3.0.