CVE-2026-25126Public exploitNetwork attack vector

Vote count manipulation via unvalidated direction values

Published Jan 29, 2026 · Updated Jan 29, 2026

Improper input validation in PolarLearn before 0-PRERELEASE-15 allows remote authenticated users to manipulate forum post vote counts. The POST /api/v1/forum/vote route accepts direction from JSON without runtime validation, and VoteServer treats any non-up, non-null value as a downvote and stores it in votes_data. A valid account is required; alternating an invalid direction with null lets one user decrease a post's score indefinitely, corrupting forum rankings and reputation data.

CVSS severity7.1
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in PolarLearn before 0-PRERELEASE-15 allows remote authenticated users to manipulate forum post vote counts. The POST /api/v1/forum/vote route accepts direction from JSON without runtime validation, and VoteServer treats any non-up, non-null value as a downvote and stores it in votes_data. A valid account is required; alternating an invalid direction with null lets one user decrease a post's score indefinitely, corrupting forum rankings and reputation data.

The record

CVE
CVE-2026-25126
Published
Jan 29, 2026
Updated
Jan 29, 2026
Vendor
PolarNL
Product
PolarLearn
Classifications
CWE-20, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0-PRERELEASE-15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

PolarNL · PolarLearnversion=< 0-PRERELEASE-15

Published CVSS scores

7.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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