CISA KEV Critical Authentication

CVE-2022-23131 — Zabbix Frontend Authentication Bypass Vulnerability

In the case of instances where the SAML SSO authentication is enabled (non-default), session data can be modified by a malicious actor, because a user login stored in the session was not verified. Malicious unauthenticated actor may exploit this issue to escalate privileges and gain admin access to Zabbix Frontend. To perform the attack, SAML authentication is required to be enabled and the actor has to know the username of Zabbix user (or use the guest account, which is disabled by default).

Published Jan 13, 2022 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: Zabbix

Urgent

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Feb 22, 2022 Detection templates (Nuclei) · 1 Proofs of concept on GitHub · 20

How the score was calculated

Confirmed exploitation (CISA KEV)+35
Public exploit/PoC (nuclei, github)+10
EPSS 95.7% (30-day exploitation probability)+15
Technical severity (critical)+10
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Confirmed

CISA KEV, listed Feb 22, 2022

EPSS FIRST

95.68%

ahead of 100% of scored CVEs · Oct 14, 2026

Affects

Zabbix

Frontend and 1 more

CVSS base

9.8

Critical · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — support.zabbix.com (NIST National Vulnerability Database)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Mar 8, 2022 — passed 1682 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Zabbix Frontend, Zabbix Zabbix).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Zabbix	Frontend	version 5.4.0 - 5.4.8	Vulnerable	CVE Program (cve.org) e CISA ADP
Zabbix	Zabbix	≥ 5.4.0 and ≤ 5.4.8version 6.0.0-alpha1	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.8	CVSS 3.1	Critical	3.9	5.9	nvd@nist.gov via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	GitHub, Inc. via GitHub Security Advisories
9.1	CVSS 3.1	Critical	3.9	5.2	security@zabbix.com via NIST National Vulnerability Database
9.1	CVSS 3.1	Critical	—	—	Zabbix via CVE Program (cve.org) e CISA ADP
5.1	CVSS 2.0	Medium	4.9	6.4	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 9.8 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-290 · Authentication Bypass by Spoofing

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed

Feb 22, 2022

Federal deadline

Mar 8, 2022

passed 1682 day(s) ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Detection templates (Nuclei)

Zabbix - SAML SSO Authentication Bypass

Proofs of concept on GitHub — 20 repositories; showing the 10 most starred

cve-2022-23131 zabbix-saml-bypass-exp ★ 155 Feb 18, 2022
cve-2022-23131 exp ★ 95 Feb 18, 2022
cve-2022-23131 ★ 29 Feb 22, 2022
Zabbix - SAML SSO Authentication Bypass ★ 15 Feb 28, 2022
CVE-2022-23131漏洞利用工具开箱即用。 ★ 11 Apr 2, 2022
Zabbix SSO Bypass ★ 8 Feb 23, 2022
CVE-2022-23131漏洞批量检测与利用脚本 ★ 8 Jul 22, 2022
CVE-2022-23131 Zabbix Server SAML authentication exploit ★ 5 Sep 18, 2024
1mxml/CVE-2022-23131 ★ 3 Feb 18, 2022
pykiller/CVE-2022-23131 ★ 2 Feb 24, 2022

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 95.68%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
Hunt retroactively in logs from before Feb 22, 2022 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
Affected products added · zabbix/zabbix
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 9.1 → 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · Published → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record published
Oct 13, 2026
Affected products added · zabbix/frontend
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
CVSS changed · 9.1
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Published
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
2022
Added to CISA KEV catalog
Feb 21, 2022 · CISA
CVE published
Jan 13, 2022 · Zabbix

Source activity

Repeated readings are counted rather than listed.

3× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

support.zabbix.com/browse/ZBX-20350
x_refsource_MISC, Issue Tracking, Patch, Vendor Advisory, CVE Program (cve.org) e CISA ADP
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
github.com/advisories/GHSA-4g73-3mxf-j47w
GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2022-23131
GitHub Security Advisories

Elsewhere on this site

Zabbix
every CVE for this vendor

2022-02
what else CISA listed that month

Authentication
same class

CWE-290
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-59788 Stored XSS vulnerability in OAuth configuration form 10d
Medium CVE-2026-59786 Active agent heartbeat missing TLS check 10d
Medium CVE-2026-59782 JavaScript preprocessing memory disclosure 10d
Medium CVE-2026-59787 SNMP trap injection in zabbix_trap_receiver.pl 10d
Medium CVE-2026-59785 Hidden host credentials inferable via multiselect.get filtering 10d
Low CVE-2026-59783 Server DoS via binary items 10d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2022-23131 is "Zabbix Frontend Authentication Bypass Vulnerability", rated Critical. It affects Frontend (Zabbix); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 95.68% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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