CVE-2026-39924Network attack vector

Account access persistence via unrevoked session tokens

Published Aug 5, 2026 · Updated Aug 5, 2026

Improper session invalidation in Flarum before 1.8.16 allows remote authenticated users to retain account access after password changes. TokensClearer handles PasswordChanged by deleting password_tokens rows but does not delete matching access_tokens rows. Exploitation requires an already valid victim token; retained session, remember, and developer tokens preserve the victim's privileges.

CVSS severity6.8
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper session invalidation in Flarum before 1.8.16 allows remote authenticated users to retain account access after password changes. TokensClearer handles PasswordChanged by deleting password_tokens rows but does not delete matching access_tokens rows. Exploitation requires an already valid victim token; retained session, remember, and developer tokens preserve the victim's privileges.

The record

CVE
CVE-2026-39924
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
Flarum
Product
Flarum
Classifications
CWE-613, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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 <1.8.16

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Flarum · Flarumversion=0 <1.8.16

Published CVSS scores

6.8VulnCheckCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
7.6VulnCheckCVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA: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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-613Insufficient Session Expiration
T1078Valid Accounts

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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