CVE-2026-15783: A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with write access to any repository to read metadata from privat

unknownCVE-2026-15783

A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with write access to any repository to read metadata from private repositories they did not have access to, including private repository owners and names, branch names, commit SHAs, commit messages, and the pushing actor. The delegated bypass endpoint resolved a rule suite directly from an attacker-supplied, encoded identifier without verifying that the requesting user could read the rule suite's repository, and because these identifiers are sequential an attacker could enumerate them across the instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.18, 3.18.12, 3.19.9, 3.20.5, and 3.21.3. This vulnerability was reported via the GitHub Bug Bounty program.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: unknown
Published: 2026-07-17
Last updated: 2026-07-17
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-15783

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-157830.27% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-15783	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[NEW] [high] Microsoft GitHub Enterprise Server: Multiple vulnerabilitiescert-bund

Recent advisories for A missing authorization

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

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