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CVE-2026-25519: Openslides Improper Access Control (CVSS 8.1)

CVE-2026-25519 is a high severity improper access control in Openslides with a CVSS score of 8.1. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Jun 17, 2026

Quick answer

Direct answer

CVE-2026-25519 is a high severity improper access control in Openslides with a CVSS score of 8.1. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
8.1HIGH
EPSS probability
0.74%
Higher than 54 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:N)Network: reachable remotely
Attack complexity (AC:H)High complexity
Privileges required (PR:N)No privileges required
User interaction (UI:N)No user interaction
Scope (S:U)Scope unchanged
Confidentiality (C:H)High confidentiality impact
Integrity (I:H)High integrity impact
Availability (A:H)High availability impact

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

About Openslides

CVE-2026-25519 affects Openslides, a product from Openslides. Before acting, confirm where Openslides runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.

What the flaw is

In plain terms: OpenSlides is a free, web based presentation and assembly system for managing and projecting agenda, motions and elections of an assembly. Prior to version 4.2.29, OpenSlides supports local logins with username and password or an optionally configurable single sign on with SAML via an external IDP. For users synced to OpenSlides via an external IDP, there is an incorrect access control regarding the local login of these users. Users can successfully login using the local login form and the OpenSlides username of a SAML user and a trivial password. This password is valid for all SAML users. This issue has been patched in version 4.2.29.

The weakness class is Improper Access Control. The software does not properly restrict who can use a resource.

Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductOpenslides
Affected versionsOpenslides from 4.2.5 before 4.2.29
PublishedFeb 4, 2026
Last modifiedJun 17, 2026
Added to CISA KEVNot listed
Assigning CNAsecurity-advisories@github.com

How to detect it

  • Inventory every instance of Openslides and record the running version against the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
  • Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.

How to fix it

  • Apply the fixed version of Openslides named in the vendor advisory.
  • If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
  • Rescan after the change to prove the exposure is gone, then close the ticket.

CTEM action plan

CTEM stageWhat to do for this CVE
ScopeAdd every business service that depends on Openslides to the current CTEM cycle.
DiscoverFind all instances, including shadow and cloud deployments, and record versions and exposure.
PrioritizeRank using EPSS and CVSS together with asset exposure and business impact.
ValidateConfirm the flaw is reachable and exploitable in your environment and that compensating controls work.
MobilizeAssign the fix to the asset owner with a due date matched to the priority, then verify closure.

CWE References

Technical References

Frequently asked questions

CVE-2026-25519 is a high severity improper access control in Openslides with a CVSS score of 8.1. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

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