Vikunja before 2.7.1 Resource Exhaustion via CalDAV VTODO RELATED-TO Entries
- Exploited
- No known exploitation
- Fix
- Fixed in 2.7.1
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 2.7.1.
- Last modified
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.27% · 19th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 8/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Vikunja, the open-source task management software, before version 2.7.1 has a resource exhaustion flaw in its CalDAV handling of VTODO RELATED-TO entries. An attacker who can reach the service remotely and has a low-privilege login can send a single crafted request that creates thousands of dummy tasks, bloating the database and overloading the event pipeline.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
Vikunja before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated CalDAV clients to create unbounded dummy tasks by sending VTODOs with thousands of RELATED-TO properties. Attackers can repeat unknown related UIDs in a single PUT request to generate thousands of task, relation, and event rows, bloating the database and overloading the event pipeline.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure3/25Reachable over the network · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity5.3/10CVSS 5.3
- No patch0/5No signal
What would change the score
- Would score about 63 if added to CISA KEV
- Would score about 58 if CISA's SSVC rates exploitation active
- Would score about 27 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 2.7.1.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- go-vikunja vikunja
fixed in 2.7.1
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123511
Is CVE-2026-123511 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-123511?
vikunja: before 2.7.1.Source: cve.now feed data
How do I fix CVE-2026-123511?
Upgrade to a fixed version: 2.7.1.Source: cve.now feed data