Vikunja before 2.7.1 Memory Exhaustion via Unbounded Avatar Size Cache
Affects Vikunja up to and including 2.7.0 on a default instance that uses the in-memory keyvalue store. Fixed in 2.7.1.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 2.7.1
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affects Vikunja up to and including 2.7.0 on a default instance Uses the default in-memory keyvalue store, which has no size cap or eviction
- Published
- Last modified
- 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? →
- 15/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- 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 before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated users to exhaust server memory by requesting avatars at many distinct sizes. Attackers can upload a noisy avatar and fetch it at each size up to 1024, caching roughly a gigabyte per account without eviction and causing the API process to be OOM-killed.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.1/10CVSS 7.1
- No patch0/5No signal
What would change the score
- Would score about 65 if added to CISA KEV
- Would score about 60 if CISA's SSVC rates exploitation active
- Would score about 22 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Affects Vikunja up to and including 2.7.0 on a default instance Uses the default in-memory keyvalue store, which has no size cap or evictionUpgrade 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-2026-123523
Is CVE-2026-123523 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
What does this mean?
The avatar cache in Vikunja has no size limit or eviction in the default in-memory store, so it can keep growing. Any authenticated user can exhaust server memory, which gets the API process OOM-killed and causes a denial of service.Source: github.com, vulncheck.com
Which versions are affected by CVE-2026-123523?
vikunja: before 2.7.1.Source: cve.now feed data
Am I affected, and how do I check?
Vikunja versions before 2.7.1 are in range, and the advisory's own test case is a default vikunja/vikunja:2.7.0 instance. The bug depends on the default in-memory keyvalue store, which has no size cap or eviction. To check a setup, look at the Vikunja version of the running instance (for example, the image tag) and whether it uses the default keyvalue store.Source: github.com, vulncheck.com
How do I fix CVE-2026-123523?
Upgrade Vikunja to version 2.7.1 or later, which is the listed fixed version. The facts list no workaround.Source: github.com, vulncheck.com