What is CVE-2026-49953?

CVE-2026-49953 is a medium-severity vulnerability in Discuz! X5.0, classified under CWE-804. CVSS score: 6.5/10. Published 2026-06-15.

How severe is CVE-2026-49953?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Discuz! X5.0

CVE-2026-49953

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…

EPSS: 0.004 (28.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Discuz! X5.0 — versions 20260320

Weakness classification (CWE)

CWE-804

References

disclosure@vulncheck.com (technical-description)
disclosure@vulncheck.com (exploit)
disclosure@vulncheck.com (third-party-advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2026-49953?: CVE-2026-49953 is a medium-severity vulnerability in Discuz! X5.0, classified under CWE-804. CVSS score: 6.5/10. Published 2026-06-15.
How severe is CVE-2026-49953?: Medium severity. CVSS v3 base score is 6.5 out of 10.