CVE-2026-25221VulnerabilityPublished 2 Feb 2026

CVE-2026-25221: polarnl PolarLearn · Cross-Site Request Forgery (CSRF)

Affects polarnl PolarLearnSource CVE Database V5

Not known to be exploited · CVSS 2.3 Low.

Data as of 26 Oct 2026, 07:57 UTC

CVSS 4.0 base score

2.3Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: Passive
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: Low
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
polarnlPolarLearn	Affected =<= v0-PRERELEASE-15	Fixed in–

AI-suggested

Organizations should immediately upgrade PolarLearn to a version that implements and verifies the OAuth state parameter in the authentication flow once available. Until a patch is released, administrators should consider disabling OAuth login providers (GitHub and Google) or restrict their use to trusted users only. Implementing additional monitoring for suspicious login behaviors and educating users about phishing and social engineering risks can reduce exploitation likelihood. Developers and administrators can also implement web application firewalls (WAFs) with rules to detect and block CSRF attempts targeting OAuth endpoints. Regularly auditing OAuth flows for proper state parameter usage and ensuring secure session management practices are critical. Finally, organizations should prepare incident response plans to address potential data integrity issues arising from this vulnerability.

Description

CVE-2026-25221 is a Cross-Site Request Forgery (CSRF) vulnerability in the OAuth 2.0 login implementation of PolarLearn versions up to 0-PRERELEASE-15. The flaw arises because the application does not implement or verify the OAuth state parameter during authentication with GitHub and Google providers. This allows attackers to trick victims into logging into the attacker’s account, causing victims’ data and academic progress to be stored under the attacker’s profile. The vulnerability leads to data loss for victims and potential information disclosure to attackers. Exploitation requires user interaction but no prior authentication. The CVSS score is low (2.3), reflecting limited impact on confidentiality and availability, but the integrity of user data is affected. No known exploits are currently reported in the wild. European organizations using PolarLearn should be aware of this risk, especially educational institutions relying on this platform for learning management.

Impact

For European organizations, particularly educational institutions and e-learning providers using PolarLearn, this vulnerability could lead to significant data integrity issues. Students or users may unknowingly have their academic progress and personal data recorded under an attacker’s account, causing confusion, loss of academic records, and potential privacy breaches. Although the confidentiality and availability impacts are low, the integrity loss could undermine trust in the platform and disrupt learning outcomes. This could also lead to compliance issues under GDPR if personal data is improperly handled or disclosed. The attack requires user interaction, so phishing or social engineering campaigns could be used to exploit this vulnerability. While no known exploits exist yet, the risk remains relevant as adoption of PolarLearn grows in Europe.

CWE-352Cross-Site Request Forgery (CSRF) (opens in a new tab)
Compound weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #3OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation
Ensure that the application is free of cross-site scripting issues (CWE-79), because most CSRF defenses can be bypassed using attacker-controlled script.
Architecture and Design
Generate a unique nonce for each form, place the nonce into the form, and verify the nonce upon receipt of the form. Be sure that the nonce is not predictable (CWE-330).
OWASP Cheat Sheets
REST Assessment (opens in a new tab)
REST Security (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V13.2.3 (opens in a new tab)
V4.2.2 (opens in a new tab)
V13.3.2 (opens in a new tab)
Attack patterns
JSON Hijacking (aka JavaScript Hijacking) (opens in a new tab)
Cross-Domain Search Timing (opens in a new tab)
Cross Site Identification (opens in a new tab)
Cross Site Request Forgery (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Feb 2026, 10:59 UTC

WeaknessesCWE-352

Technical details

References

Community reviews

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