CVE-2026-40587Public exploitNetwork attack vector

Persistent account access via uninvalidated sessions

Published Apr 21, 2026 · Updated Apr 21, 2026

Insufficient session expiration in blueprintUE Self-Hosted Edition before 4.2.0 allows attackers with a stolen session to retain account access. The password-change and reset handlers update the users-table password but never delete or invalidate sessions associated with the user ID. Exploitation requires an already compromised authenticated session, which remains usable for account actions until natural expiry even after the password changes.

CVSS severity6.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient session expiration in blueprintUE Self-Hosted Edition before 4.2.0 allows attackers with a stolen session to retain account access. The password-change and reset handlers update the users-table password but never delete or invalidate sessions associated with the user ID. Exploitation requires an already compromised authenticated session, which remains usable for account actions until natural expiry even after the password changes.

The record

CVE
CVE-2026-40587
Published
Apr 21, 2026
Updated
Apr 21, 2026
Vendor
blueprintUE
Product
blueprintUE Self-Hosted Edition
Classifications
CWE-613, T1550.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 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=< 4.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

blueprintUE · blueprintUE Self-Hosted Editionversion=< 4.2.0

Published CVSS scores

6.5GitHubCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-613Insufficient Session Expiration
T1550.004Use Alternate Authentication Material: Web Session Cookie

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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