CVE-2026-25519Network attack vector

SAML account impersonation via shared dummy password

Published Feb 4, 2026 · Updated Feb 4, 2026

Authentication bypass in OpenSlides 4.2.5 through 4.2.28 allows remote attackers to impersonate SAML-synced users via local login. The authentication service verifies a shared dummy hash when a SAML user's password field is empty, accepting the corresponding trivial password instead of rejecting passwordless accounts. SAML single sign-on must be configured, and successful login grants the target user's access to meeting data and actions.

CVSS severity9.8
Critical
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in OpenSlides 4.2.5 through 4.2.28 allows remote attackers to impersonate SAML-synced users via local login. The authentication service verifies a shared dummy hash when a SAML user's password field is empty, accepting the corresponding trivial password instead of rejecting passwordless accounts. SAML single sign-on must be configured, and successful login grants the target user's access to meeting data and actions.

The record

CVE
CVE-2026-25519
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
Intevation
Product
OpenSlides
Classifications
CWE-284, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 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=< 4.2.29

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Intevation · OpenSlidesversion=< 4.2.29

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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-284Improper Access Control
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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