# CVE-2026-64638: WordPress WordPress

- Exploited (CISA KEV): no
- Published: 2026-08-07
- CVSS: 8.9 HIGH (v4.0)
- EPSS: 0.9% (59th percentile)
- CWE: CWE-79

WordPress is vulnerable to a pre-auth reflected XSS vulnerability on the login screen.

Via a specially crafted malicious third-party website hosted by an attacker, it is possible for this to be escalated to an RCE vulnerability with conditions outside of the attackers control. This requires successful social engineering of and explicit interaction by the target victim.

This issue affects all versions of WordPress. Version 7.0.3 has been released, containing a fix for the vulnerability, and as a courtesy to users on older branches the fix has been backported to all branches back to 4.7.

Discovered and responsibly disclosed by [the team at pwn.ai](https://pwn.ai/).

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Rule published | 2026-08-07 | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-09-16 | 40 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2026-08-07 · updated · rule d3852d0891634686a46114069c6dff1c
  > Wordpress - XSS - CVE:CVE-2026-64638. Previous action: Block. New action: N/A. Rule metadata description refined. Detection unchanged.
  Source: https://developers.cloudflare.com/changelog/post/2026-08-07-waf-release/
- 2026-08-07 · updated · rule 5bdf578fff504b8cbe3b7f699ab5ed95
  > Wordpress - XSS - CVE:CVE-2026-64638. Previous action: Block. New action: N/A. Rule metadata description refined. Detection unchanged.
  Source: https://developers.cloudflare.com/changelog/post/2026-08-07-waf-release/

### F5

- 2026-09-16 · new · rule 200201057
  > Added: signature 200201057 "WordPress Unauthenticated XSS" (Cross Site Scripting (XSS), risk High), systems: WordPress. References: CVE-2026-64638.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: passed (0 of 3 requests blocked), template CVE-2026-64638, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: partial (2 of 3 requests blocked), template CVE-2026-64638, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2026-64638 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-64638