What is CVE-2026-23929?

CVE-2026-23929 is Prototype pollution leading to stored XSS. The supplied enrichment data classifies it as Remote Code Exec mapped to CWE-1321 CWE-1321.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-23929. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-23929 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

4 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-23929 using CVSS 8.5, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

Workarounds are not confirmed from current sources. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

highRemote Code Execpublic exploit

CVE-2026-23929

CVE-2026-23929 — Prototype pollution leading to stored XSS

Prototype pollution vulnerability in searchParamsToObject() is leading to a persistent XSS in Maps. URL parameter processing was not filtering dangerous properties like __proto__, combined with jQuery's unsafe element creation that traversed the prototype chain.

Published Aug 18, 2026Updated Aug 18, 2026Sources: NVD, Zabbix (CNA), GitHub, SOCRadar CTI

Triage

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

Exploitation

Exploit code

public exploit, none observed

EPSS

ahead of 0% of scored CVEs

Affects

Zabbix

3 products listed

CVSS base

8.5

high

Remediation

The vendor's own words where we have them.

Update the affected components to their respective fixed versions.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Zabbix	Zabbix	6.0.44 to <= 6.0.45	Vulnerable
Zabbix	Zabbix	7.0.22 to <= 7.0.24	Vulnerable
Zabbix	Zabbix	7.4.6 to <= 7.4.8	Vulnerable

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Source
8.5	CVSS 4.0	high	—	—	Zabbix (CNA)

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-1321 · Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Modify Application Data:LIKELIHOOD:High
DoS: Crash, Exit, or Restart:LIKELIHOOD:High

Mitigation: By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.

Weakness & attack patterns

CWE-1321

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-1 · Accessing Functionality Not Properly Constrained by ACLsCAPEC-180 · Exploiting Incorrectly Configured Access Control Security LevelsCAPEC-77 · Manipulating User-Controlled Variables

T1574.010Hijack Execution Flow: ServicesFile Permissions Weakness

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Detection

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

Monitor for scanner or exploit-pattern traffic after 4 public PoC repositories were reported.

EDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 8.5
Aug 18, 2026 · NVD
Initial · CVE published
Aug 18, 2026 · NVD

References

1 on the record

support.zabbix.com/browse/ZBX-28068
Vendor Advisory

Elsewhere on this site

Zabbixevery CVE for this vendor
Remote Code Execsame class
CWE-1321other pages naming this weakness

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 record1

What should defenders know first?

CVE-2026-23929 is Prototype pollution leading to stored XSS, a high vulnerability affecting Zabbix from Zabbix. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-23929. Public exploit evidence is: 4 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 8.5 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.