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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-49953

24
FAUCET Score

Discuz! X5.0 releases 20260320 through 20260610 contains a CAPTCHA bypass vulnerability that allows unauthenticated remote attackers to defeat challenge controls by exploiting limited complexity and predictable character sets in generated CAPTCHA images. Attackers can train a custom optical character recognition model against collected CAPTCHA samples to reliably predict challenge text, bypassing protections on login, registration, and other functionality from automated abuse.

First published: Jun 15, 2026Last modified: Jun 15, 2026

Impacted Technologies

VendorProductVersion(s)CPE
Discuz!Discuz! X5.0
>= 20260320, <= 20260610CNA affecteddefault unknown

CVSS Data

CVSS version used by this source: 4.0

6.9MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
VS Confidentiality
LOW
VS Integrity
LOW
VS Availability
NONE
SS Confidentiality
NONE
SS Integrity
NONE
SS Availability
NONE
Exploit Maturity
NOT_DEFINED
CvssVersion
4.0

Exploit Intelligence

EPSS Score
0.36%
Probability of exploitation in next 30 days
EPSS Percentile
28.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0036 is in the 17th percentile among its peer group of 23,705 CVEs.

Social Chatter

No social media mentions found for this CVE.

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

seclists.org / fulldisclosure/2026/Jun/4
karmainsecurity.com / chaining-bugs-in-discuz-from-race-condition-to-rce
karmainsecurity.com / KIS-2026-10
vulncheck.com / advisories/discuz-x5-0-captcha-bypass-via-predictable-character-set