CVE-2026-15783

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 61/100
Published: 2026-07-17 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: X
AT: None
VC: Low
VI: None
VA: None

Description

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.

Weakness Classification (1)

Bug Bounty Relevance

61 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

5.3 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/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

EPSS — Exploitation Probability

0.45%
Raw Score 0.004490
Percentile 39.0%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00449
2026-10-28
0.00449

Intelligence Sources

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