Insufficient HTML Sanitization Allows User-Controlled DOM Elements to Overwrite Server-Initialized Data Islands and Trigger Unintended Server-Side POST Requests
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.3%
exploitation probability
0.3%top 74% of all CVEs
observed exploitation
nono source reports it
An improper neutralization of input vulnerability was identified in GitHub Enterprise Server that allowed user-supplied HTML to inject DOM elements with IDs that collided with server-initialized data islands. These collisions could overwrite or shadow critical application state objects used by certain Project views, leading to unintended server-side POST requests or other unauthorized backend interactions. Successful exploitation requires an attacker to have access to the target GitHub Enterprise Server instance and to entice a privileged user to view crafted malicious content that includes conflicting HTML elements. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.18.3, 3.17.9, 3.16.12, 3.15.16, and 3.14.21.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
GitHub · Enterprise ServerReferences
https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.21https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.16https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.12https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.9https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.3