CVE-2026-123498
LOW
Published Nov 8, 2026
Modified Nov 9, 2026
Description
Vikunja veans before 2.7.1 contains a prompt injection vulnerability that allows project members with write access to inject instructions by setting project titles or task content rendered verbatim inside the coding agent's authoritative instruction block. Attackers can craft ProjectTitle or task descriptions that the prime hook loads on SessionStart and PreCompact, causing the agent to modify the developer's checkout or run commands.
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CVSS v3.1 Score
3.7
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N
EPSS — Exploit Prediction
0.0015
Probability of exploitation
0.05%
Percentile rank
EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.
References
Frequently Asked Questions
What is CVE-2026-123498? +
Vikunja veans before 2.7.1 contains a prompt injection vulnerability that allows project members with write access to inject instructions by setting project titles or task content rendered verbatim inside the coding agent's authoritative instruction block. Attackers can craft ProjectTitle or task descriptions that the prime hook loads on SessionStart and PreCompact, causing the agent to modify the developer's checkout or run commands. It has a CVSS v3.1 base score of 3.7 (LOW).
How severe is CVE-2026-123498? +
CVE-2026-123498 has a CVSS v3.1 score of 3.7 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-123498? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.
