Improper input validation in Polarlearn
CVE-2026-25126
PolarLearn is a free and open-source learning program. Prior to version 0-PRERELEASE-15, the vote API route (`POST /api/v1/forum/vote`) trusts the JSON body’s `direction` value without runtime validation. TypeScript types are not enforced at runtime, so an attacker can send arbitrary strings (e.g., `"x"`) as `direction`. Downstream (`VoteServer`) treats any non-`"up"` and non-`null` value as a downvote and persists the invalid value in `votes_data`. This can be exploited to bypass intended business logic. Version 0-PRERELEASE-15 fixes the vulnerability.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.003 (26.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N.
Affected products
- Polarlearn
- Polarnl Polarlearn — versions < 0-PRERELEASE-15
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-25126?
- CVE-2026-25126 is a high-severity vulnerability in Polarlearn, classified under Improper Input Validation. CVSS score: 7.1/10. Published 2026-01-29.
- How severe is CVE-2026-25126?
- High severity. CVSS v3 base score is 7.1 out of 10.