Unauthenticated rate-limit bypass via spoofed IP headers
Published Mar 20, 2026 · Updated Mar 20, 2026
Rate-limit bypass in Vikunja allows remote attackers to send unlimited requests to unauthenticated endpoints by spoofing IP headers. The unauthenticated-route middleware keys requests with Echo Context.RealIP, which trusts client-controlled X-Forwarded-For or X-Real-IP values by default. Starting with 0.8, versions before 2.2.0 are exposed when no reverse proxy overwrites those headers, enabling request flooding or password brute-force attempts.
Summary
What happened
Rate-limit bypass in Vikunja allows remote attackers to send unlimited requests to unauthenticated endpoints by spoofing IP headers. The unauthenticated-route middleware keys requests with Echo Context.RealIP, which trusts client-controlled X-Forwarded-For or X-Real-IP values by default. Starting with 0.8, versions before 2.2.0 are exposed when no reverse proxy overwrites those headers, enabling request flooding or password brute-force attempts.
The record
- CVE
- CVE-2026-29794
- Published
- Mar 20, 2026
- Updated
- Mar 20, 2026
- Vendor
- Vikunja
- Product
- Vikunja
- Classifications
- CWE-807, T1110
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 20, 2026CVE publishedPublication date reported by the CVE source.
- Mar 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.8, < 2.2.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GitHub advisory rate-limit bypass proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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