CVE-2026-39985Network attack vector

User redirection via unchecked login URL

Published Apr 9, 2026 · Updated Apr 9, 2026

Open redirect in ACElab LORIS before 27.0.3 and LORIS 28.0.0 allows remote attackers to redirect users to arbitrary sites after login. The login success handler assigns the untrusted redirect parameter directly to window.location.href without parsing the URL or checking its origin. Exploitation requires a user to follow a crafted link and complete login; the bounded result is navigation to an attacker-chosen site.

CVSS severity4.3
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Open redirect in ACElab LORIS before 27.0.3 and LORIS 28.0.0 allows remote attackers to redirect users to arbitrary sites after login. The login success handler assigns the untrusted redirect parameter directly to window.location.href without parsing the URL or checking its origin. Exploitation requires a user to follow a crafted link and complete login; the bounded result is navigation to an attacker-chosen site.

The record

CVE
CVE-2026-39985
Published
Apr 9, 2026
Updated
Apr 9, 2026
Vendor
ACElab
Product
LORIS
Classifications
CWE-601, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 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=< 27.0.3
  2. Affected versionversion=>= 28.0.0, < 28.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ACElab · LORISversion=< 27.0.3; version=>= 28.0.0, < 28.0.1

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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.

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-601URL Redirection to Untrusted Site ('Open Redirect')
T1204.001User Execution: Malicious Link

Public exploit references

No public exploit references are available in this record.

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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