CyberSecBulletin
CVE-2026-81826NVD status: Deferred

flowintel: Session Fixation

Published Updated By the CyberSecBulletin desk

CVE-2026-81826 is a critical-severity session fixation vulnerability in flowintel, with a CVSS 4.0 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected flowintel versions: 3.3.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.41% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of flowintel you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Flowintelflowintel3.3.0 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
PresentThe target must be in a specific state or configuration for the attack to work.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
NoneNo loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA.

Official description

Affected versions of Flowintel do not revoke existing authenticated sessions when a user’s password is changed. This means that if an attacker already possesses a valid session—for example, from prior access or a stolen session token—the victim changing their password does not terminate that attacker’s access. The session remains usable until it expires naturally. The upstream commit describes this directly as: “session keeps working until it expires.” The fix detects password changes and explicitly invokes _invalidate_user_sessions(user.id) after the database update. This is applied in both edit_user_core() and admin_edit_user_core(). Version impacted >=3.3.0

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Session Fixation

Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.

How developers prevent this class of flaw

  • Invalidate any existing session identifiers prior to authorizing a new user session.
  • For platforms such as ASP that do not generate new values for sessionid cookies, utilize a secondary cookie. In this approach, set a secondary cookie on the user's browser to a random value and set a session variable to the same value. If the session variable and the cookie value ever don't match, invalidate the session, and force the user to log on again.
  • Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.

More Session Fixation vulnerabilities (CWE-384)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in flowintel

All flowintel vulnerabilities

Recent Session Fixation vulnerabilities

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