Public proof of concept

CVE-2026-18937

A public proof of concept exists; no exploitation attested.

Published2026-08-19
WeaknessCWE-94

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

The Broken Link Checker WordPress plugin before 2.4.12 does not limit which query variables it accepts from user input on sites using plain permalinks, allowing unauthenticated users to overwrite arbitrary PHP global variables, and to execute arbitrary code on the server when a classic (non-block) is active.

Timeline

dates in UTC

2026-08-1906:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-18937?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-18937?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-18937 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

read 2026-10-23 19:25 UTC

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: 1 repository, unverifiedabraxas/CVE-2026-18937

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionnone2026-08-19
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.192026-08-19
CISA-ADPweakness (CWE)CWE-942026-08-19
FIRST EPSSEPSS score2.0 %2026-10-23
PoC-in-GitHubproof of concept1read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Published: 2026-08-19
Last Modified: 2026-08-26
NVD status: Deferred

Frequently asked questions

What is CVE-2026-18937?

Is CVE-2026-18937 actively exploited?

Active exploitation of CVE-2026-18937 has not been confirmed. Its EPSS score was 2.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-18937?

CVE-2026-18937 has a CVSS v3 base score of 9 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

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