CVE-2026-105829CWE-80

CVE-2026-105829

Medium · published October 8, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
9.9
In the wild
Unconfirmed
What it is

League CommonMark from 1.3.0 before 2.10.2 contains a cross-site scripting vulnerability that allows users posting Markdown to bypass the DisallowedRawHtml extension by ending raw HTML with a bare disallowed tag name. Attackers can place a lone <script or <iframe line followed by a block supplying attributes like src or onload, executing stored scripts in viewers' browsers under default GFM settings.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
EPSS
0.00204 · 9.9th percentile
Weakness
CWE-80 · Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Published
2026-10-08T19:17Z
References (3)
https://github.com/thephpleague/commonmark/security/advisories/GHSA-97jj-33gv-5xf9 · [email protected]https://www.vulncheck.com/advisories/league-commonmark-1.3.0-before-2.10.2-stored-xss-via-disallowedrawhtml-bypass · [email protected]https://github.com/thephpleague/commonmark/security/advisories/GHSA-97jj-33gv-5xf9 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 10 OCT 03:27Z
    EPSS moved — → 0%
    epss
  • 08 OCT 14:10Z
    League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass
    cvelistv5
  • 08 OCT 14:10Z
    League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass
    cvelistv5