vikunja: Weak Password Recovery Mechanism for Forgotten Password
CVE-2026-28268 is a critical-severity weak password recovery mechanism for forgotten password vulnerability in vikunja from Go-vikunja, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected vikunja versions: < 2.1.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.74% chance of exploitation within 30 days, higher than 55% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of vikunja you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Go-vikunja | vikunja | < 2.1.0 | Not stated |
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
- NoneNo account or login is needed.
- 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
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
Vikunja is an open-source self-hosted task management platform. Versions prior to 2.1.0 have a business logic vulnerability exists in the password reset mechanism of vikunja/api that allows password reset tokens to be reused indefinitely. Due to a failure to invalidate tokens upon use and a critical logic bug in the token cleanup cron job, reset tokens remain valid forever. This allows an attacker who intercepts a single reset token (via logs, browser history, or phishing) to perform a complete, persistent account takeover at any point in the future, bypassing standard authentication controls. Version 2.1.0 contains a patch for the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Weak Password Recovery Mechanism for Forgotten Password
The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.
How developers prevent this class of flaw
- Make sure that all input supplied by the user to the password recovery mechanism is thoroughly filtered and validated.
- Do not use standard weak security questions and use several security questions.
- Make sure that there is throttling on the number of incorrect answers to a security question. Disable the password recovery functionality after a certain (small) number of incorrect guesses.
More Weak Password Recovery Mechanism for Forgotten Password vulnerabilities (CWE-640)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in vikunja
- 8.8 High severity
- 7.1 High severity
- 7.1 High severity
Recent Weak Password Recovery Mechanism for Forgotten Password vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 8.1 High severity
- 8.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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