CVE-2025-41075Network attack vector

Unauthenticated service degradation via infinite redirect loop

Published Nov 20, 2025 · Updated Nov 20, 2025

Infinite redirect loop in LimeSurvey 6.13.0 allows remote attackers to degrade service by directly requesting the /optin endpoint. The endpoint returns HTTP redirects that never reach a terminating response, causing clients or servers to continue processing the loop. No authentication or user interaction is required, and the bounded consequences are resource exhaustion, service degradation, or browser instability.

CVSS severity6.9
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Infinite redirect loop in LimeSurvey 6.13.0 allows remote attackers to degrade service by directly requesting the /optin endpoint. The endpoint returns HTTP redirects that never reach a terminating response, causing clients or servers to continue processing the loop. No authentication or user interaction is required, and the bounded consequences are resource exhaustion, service degradation, or browser instability.

The record

CVE
CVE-2025-41075
Published
Nov 20, 2025
Updated
Nov 20, 2025
Vendor
LimeSurvey GmbH
Product
LimeSurvey
Classifications
CWE-835, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 20, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 20, 2025Record 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=6.13.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LimeSurvey GmbH · LimeSurveyversion=6.13.0

Published CVSS scores

6.9Spanish National Cybersecurity Institute, S.A. (INCIBE)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
7.5National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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