CVE-2026-18937: The Broken Link Checker WordPress plugin before 2.4.12 does not limit which query variables it accepts from us

Q: How do I fix CVE-2026-18937?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Q: Is CVE-2026-18937 being exploited?

CVE-2026-18937 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-18937 affect?

CVE-2026-18937 affects affected software. Severity is critical (CVSS 9.0). 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 execu

Q: How urgent is CVE-2026-18937?

Priority 57/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.0REMOTE

CVE-2026-18937 is a critical-severity flaw (CVSS 9.0) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	2.0% (top 19%)
CISA exploited list	No
Weakness	CWE-94
Published	2026-08-19
Last modified	2026-08-26

Publisher (CNA): WPScan

Last updated 2026-08-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-19 06:17 UTCPublished CVE record published
2026-08-26 16:30 UTCUpdated Record last modified

Exact fixes by distribution

Fedora ELN · rust-snpguest · FIXED · 0.11.0-1.eln159 · FEDORA-2026-baa01ba6c8 · source

sudo dnf upgrade --advisory=FEDORA-2026-baa01ba6c8

Fedora 46 · rust-sev · FIXED · 8.0.0-1.fc46 · FEDORA-2026-df06b5fb0c · source

sudo dnf upgrade --advisory=FEDORA-2026-df06b5fb0c

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: abraxas/CVE-2026-18937 (0 stars)
Write-up: wpscan.com/vulnerability/a23b76eb-107d-4e02-8eae-c3c5fa5b003d/
Nuclei scan template: WordPress Broken Link Checker < 2.4.12 - Remote Code Execution

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-18937?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-18937 being exploited?

CVE-2026-18937 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-18937 affect?

CVE-2026-18937 affects affected software. Severity is critical (CVSS 9.0). 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 execu

How urgent is CVE-2026-18937?

Priority 57/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

WordPress vulnerabilities · PHP vulnerabilities

References

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