CVE-2026-10585

Published Jun 30, 2026

Last updated 7 days ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-10585 is a stored cross-site scripting (XSS) vulnerability found in GitHub Enterprise Server. An authenticated attacker can exploit this by embedding a specially crafted payload within the title of a Discussion in the Q&A category. When another authenticated user views this Discussion, the malicious JavaScript is executed in their browser. The vulnerability arises because the `AnsweredQuestionStructuredDataComponent` fails to properly escape user-controlled Discussion titles before embedding them into a `<script type="application/ld+json">` block. This allows the attacker to break out of the JSON-LD block and inject arbitrary markup. Furthermore, attackers can escalate this injection to a full XSS attack by leveraging JSONP callback support in the REST API to bypass the Content Security Policy (CSP) of GitHub Enterprise Server.

Description: A stored cross-site scripting vulnerability was identified in GitHub Enterprise Server that allowed an authenticated attacker to execute arbitrary JavaScript in another user's browser by injecting a crafted payload into the title of a Discussion in the Q&A category. The AnsweredQuestionStructuredDataComponent did not escape user-controlled Discussion titles before embedding them in a <script type="application/ld+json"> block, allowing the title to break out of the script context. The injection was escalated to a full cross-site scripting attack on GitHub Enterprise Server by leveraging JSONP callback support in the REST API to bypass the Content Security Policy. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.4, 3.19.8, 3.18.11, 3.17.17, 3.16.20. This vulnerability was reported via the GitHub Bug Bounty program.
Source: product-cna@github.com
NVD status: Analyzed
Products: enterprise_server

Risk scores

CVSS 4.0

Type: Secondary
Base score: 6.3
Impact score: -
Exploitability score: -
Vector string: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:H/SI:H/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
Severity: MEDIUM

CVSS 3.1

Type: Primary
Base score: 5.4
Impact score: 2.7
Exploitability score: 2.3
Vector string: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Severity: MEDIUM

Weaknesses

product-cna@github.com: CWE-79

Hype score: Not currently trending

two vulnerabilities I reported to @github have been released! 🎉 - CVE-2026-9132 (Missing authorization to private repo disclosure) - CVE-2026-10585 (Stored XSS) https://t.co/1ZyQn6Llc9
@_seokchan_yoon
9 Jul 2026
3117 Impressions
0 Retweets
51 Likes
8 Bookmarks
2 Replies
0 Quotes

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "09FDB053-8EF5-4CAF-9C05-090985C57A77",
            "versionEndExcluding": "3.16.20",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "F0612BD3-C04E-4A34-ACEF-4D1F4F723E47",
            "versionEndExcluding": "3.17.17",
            "versionStartIncluding": "3.17.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "0553891C-ED0B-4D2C-A832-29996F0CE8B2",
            "versionEndExcluding": "3.18.11",
            "versionStartIncluding": "3.18.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "E67B4A61-E777-4B50-8DFC-DDF6292C4771",
            "versionEndExcluding": "3.19.8",
            "versionStartIncluding": "3.19.0",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "A51E85E4-FF55-497C-A39F-F69E224E63BD",
            "versionEndExcluding": "3.20.4",
            "versionStartIncluding": "3.20.0",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.