CVE-2026-66674: WordPress Simple Cloudflare Turnstile plugin <= 1.42.1 - Captcha Bypass vulnerability
Deferred
Published 10-09-2026Last modified 10-09-2026
Vulnerability summary
CVE-2026-66674 is a medium (CVSS 5.6) Authentication Bypass by Spoofing vulnerability in elliot sowers/ relywp simple cloudflare turnstile. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.7% of scored vulnerabilities.
CVSS score
5.6/10
010
Medium · v3.1 (CVE.org)EPSS score
0.25%
0%100%
Low · +0.05 pp in 30 daysKEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded
Timeline
- 10-09-2026PublishedVulnerability first disclosed.
- 10-09-2026Last modifiedVulnerability information updated.
Description
Unauthenticated Bypass Vulnerability in Simple Cloudflare Turnstile <= 1.42.1 versions.
CVSS metrics
3 scores · 3 sources · 1 versionMedium 5.6Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:LSources3 sources · 5.3–5.6
- NVDNIST5.6MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
- wordfenceSource5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NDiffers
EPSS trend
Probability
0.25%
Chance of exploitation in the next 30 days
Percentile
16%
Versus all other CVEs
30-day change
Increase +0.05 pp
From 0.20% on 22-09-2026
22-09-202622-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-290Authentication Bypass by SpoofingThis attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
- CWE-804Guessable CAPTCHAThe product uses a CAPTCHA challenge, but the challenge can be guessed or automatically recognized by a non-human actor.
Affected systems
Elliot sowers/ relywp1 product
- simple cloudflare turnstile≥ n/a, ≤ 1.42.1
Wordpress1 product
- simple-cloudflare-turnstile≤ 1.42.1 (fixed in 1.42.3)
2 vendors · 2 products
References
2 links- patchstack.com/database/…VDB Entry