Vulnerability Report

CVE-2026-3854

RCE

Title: Improper neutralization of special elements in GitHub Enterprise Server

RCE

Proof Of Concept

PoC Available for CVE-2026-3854

CWE Category CWE-77
Published Date Mar 10, 2026
Modified Date Apr 28, 2026
Exploit Status Available
Score 8.7 CVSS v4.0
Exploit Probability (EPSS)
0.34%

Vulnerability Summary

CVE-2026-3854: An improper neutralization of special elements vulnerability was identified in GitHub Enterprise Server that allowed an attacker with push access to a repository to achieve remote code execution on the instance. During a git push operation, user-supplied push option values were not properly sanitized before being included in internal service headers. Because the internal header format used a delimiter character that could also appear in user input, an attacker could inject additional metadata fields through crafted push option values. This vulnerability was reported via the GitHub Bug Bounty program and has been fixed in GitHub Enterprise Server versions 3.14.25, 3.15.20, 3.16.16, 3.17.13, 3.18.7 and 3.19.4.

Impacted Vendors

B
blackberry 1
G
github 1

Reference Links

https://docs.github.com/en/[email protected]/admin/release-notes#3.14.24 https://docs.github.com/en/[email protected]/admin/release-notes#3.15.19 https://docs.github.com/en/[email protected]/admin/release-notes#3.16.15 https://docs.github.com/en/[email protected]/admin/release-notes#3.17.12 https://docs.github.com/en/[email protected]/admin/release-notes#3.18.6 https://docs.github.com/en/[email protected]/admin/release-notes#3.19.3
CVSS v4.0
Source Entity [email protected]
Severity HIGH
8.7
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
N/A
RAW VECTOR CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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
CVSS v3.1
Source Entity [email protected]
Severity HIGH
8.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-3854 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/lysophavin18/CVE-2026-3854-PoC
View Code
GitHub https://github.com/LACHHAB-Anas/Exploit_CVE-2026-3854
View Code
GitHub https://github.com/simondankelmann/cve-2026-3854-test
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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

Affected Stack

No specific products linked.