CVE-2018-6389

In WordPress through 4.9.2, unauthenticated attackers can cause a denial of service (resource consumption) by using the large list of registered .js files (from wp-includes/script-loader.php) to construct a series of requests to load every file many times.

CVSS: 7.5High
Exploited in the wild: Not knownPublic exploit code; not in CISA KEV
EPSS: 72.7%chance of exploitation in the next 30 daystop 0.6% of scored CVEsFIRST score of 11 Nov 2026
Fix: Not stated by the vendorno fixed release in the CVE record
Published: 6 Feb 2018analysed here 12 Nov 2026

Summary

Triage

Attack surface: Server-side
Exploitable: At runtime
Attack vector: network
Weakness: CWE-400 Uncontrolled Resource Consumption
Can a WAF block it?: Partly. See why

The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.

Affected products

Products named in our analysis

wordpress:wordpress

Fix and mitigation

WAF and other mitigations

Can a WAF block it? Partly. Uncontrolled resource consumption: WAF rate limits and request-size limits reduce the impact, but do not fix the bug.

Also consider: rate limit · CDN

Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

Remediation steps (AI-written)

Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.

Exploitation evidence

CISA KEV catalog: Not listed as of our last sync.
Public exploit code: Yes: 1 on Exploit-DB · 22 GitHub proofs of concept

Exploit-DB

WordPress Core - 'load-scripts.php' Denial of Servicedos, 5 Feb 2018

GitHub proofs of concept

s0md3v/Shiva131 stars
safebuffer/CVE-2018-638983 stars
ItinerisLtd/trellis-cve-2018-638913 stars
knqyf263/CVE-2018-638910 stars

and 18 more repositories

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

Timeline

5 Feb 2018First public exploit or proof of concept
6 Feb 2018Published2 days later
5 Aug 2024CVE record last updated2,372 days (about 6 years) later
12 Nov 2026Analysed by vulneraibility.com829 days (about 2 years) later

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Metric	Value	What it means
Attack vector	NetworkReachable over the internet or any routable network.	Reachable over the internet or any routable network.
Attack complexity	LowRepeatable attack, no special conditions.	Repeatable attack, no special conditions.
Privileges required	NoneThe attacker needs no prior access.	The attacker needs no prior access.
User interaction	NoneNo victim action needed.	No victim action needed.
Scope	UnchangedImpact stays within the vulnerable component.	Impact stays within the vulnerable component.
Confidentiality	NoneNo data disclosure.	No data disclosure.
Integrity	NoneNo unauthorised modification.	No unauthorised modification.
Availability	HighFull outage possible.	Full outage possible.

Common questions

Is CVE-2018-6389 being exploited?

Not confirmed. CVE-2018-6389 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 73% probability of exploitation in the next 30 days.

How severe is CVE-2018-6389?

CVE-2018-6389 is rated High with a CVSS score of 7.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2018-6389?

Not known from our data. No patch reference has been recorded for CVE-2018-6389, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.

What does CVE-2018-6389 affect?

CVE-2018-6389 affects wordpress:wordpress. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

References

NVD CVE.org CVE Details Source

8 references in the CVE record, grouped by the tags the record gives them.

Exploits (1)

exploit-db.com /exploits/43968/

Where the data on this page comes from

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
FIRST EPSS: exploit probability and percentile
Exploit-DB: published exploits
PoC-in-GitHub: GitHub repositories that claim a proof of concept

Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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