CVE-2026-23933

Authentication bypass via hardcoded session key

Published Aug 18, 2026 · Updated Aug 19, 2026

Authentication bypass in Zabbix 7.4.0 through 7.4.10 allows remote attackers to access Frontend sessions via forged cookies in SAML guest deployments. The database seed erroneously contains the cryptographic key used to sign Frontend session cookies, so the application relies on a pre-seeded secret instead of a deployment-generated one. Reachability is currently limited to environments that enable both SAML authentication and guest users; in those cases an unauthenticated attacker with Frontend access can mint valid session cookies and act as another user.

CVSS severity7.7
High
EPSS probability0.20%
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 Zabbix 7.4.0 through 7.4.10 allows remote attackers to access Frontend sessions via forged cookies in SAML guest deployments. The database seed erroneously contains the cryptographic key used to sign Frontend session cookies, so the application relies on a pre-seeded secret instead of a deployment-generated one. Reachability is currently limited to environments that enable both SAML authentication and guest users; in those cases an unauthenticated attacker with Frontend access can mint valid session cookies and act as another user.

The record

CVE
CVE-2026-23933
Published
Aug 18, 2026
Updated
Aug 19, 2026
Vendor
Zabbix
Product
Zabbix
Classifications
CWE-259, T1550.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 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=7.4.0 <=7.4.10 changes=[{"at":"7.4.11","status":"unaffected"}]

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Zabbix · Zabbixversion=7.4.0 <=7.4.10 changes=[{"at":"7.4.11","status":"unaffected"}]

Published CVSS scores

7.7ZabbixCVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-259Use of Hard-coded Password
T1550.004Web Session Cookie

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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