CVE-2026-18937

CRITICALPre-NVD 9.09.0—
EchelonGraph scoreHIGH confidence

Score 9.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-19. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
9.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.0Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.0
EG Score
9.0(high)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

August 19, 2026

Last Modified

August 19, 2026

Advisory Details (1)

Auto-updated Aug 19, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Broken Link Checker < 2.4.12 – Unauthenticated RCE via Query Variable Injection | CVE 2026-18937 | Plugin Vulnerabilities

https://wpscan.com/vulnerability/a23b76eb-107d-4e02-8eae-c3c5fa5b003d/

Vendor Advisories for CVE-2026-18937(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 22× in last 7d / 22× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 06:41 UTCGHSA enrichment
  2. 2026-08-21 02:59 UTCGHSA enrichment
  3. 2026-08-20 23:16 UTCEG score recompute
  4. 2026-08-20 23:16 UTCGHSA enrichment
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-20 19:35 UTCGHSA enrichment
  7. 2026-08-20 15:53 UTCGHSA enrichment
  8. 2026-08-20 12:11 UTCGHSA enrichment
  9. 2026-08-20 08:29 UTCGHSA enrichment
  10. 2026-08-20 04:47 UTCGHSA enrichment
  11. 2026-08-20 01:04 UTCGHSA enrichment
  12. 2026-08-19 21:21 UTCEG score recompute
  13. 2026-08-19 21:21 UTCGHSA enrichment
  14. 2026-08-19 17:24 UTCEG score recompute
  15. 2026-08-19 17:24 UTCGHSA enrichment
  16. 2026-08-19 17:03 UTCEPSS rescore
  17. 2026-08-19 16:44 UTCEG score recompute▲ 9.00
  18. 2026-08-19 16:44 UTCGHSA enrichment
  19. 2026-08-19 16:43 UTCMITRE cvelistV5CVSS v3 → 9 · severity → CRITICAL
  20. 2026-08-19 06:21 UTCNVD update
  21. 2026-08-19 06:17 UTCEG score recompute
  22. 2026-08-19 06:17 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18937?
CVE-2026-18937 is a critical vulnerability published on August 19, 2026. 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)…
When was CVE-2026-18937 disclosed?
CVE-2026-18937 was first published in the National Vulnerability Database on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18937 actively exploited?
CVE-2026-18937 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 67.1% of all scored CVEs.
What is the CVSS score of CVE-2026-18937?
CVE-2026-18937 has a CVSS v3.1 base score of 9.0 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-18937?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18937, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-18937

Explore →

Is Your Infrastructure Affected by CVE-2026-18937?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs