Cyber Resilience

CVE-2026-49959

HighPublic PoCRCEUpdated

Published: 09 June 2026

Published
09 June 2026
Modified
17 June 2026
KEV Added
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Patch
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CVSS Score v4 8.7 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
EPSS Score 0.0095 56.7th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-49959 is a high-severity OS Command Injection (CWE-78) vulnerability. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 43.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

Hermes WebUI before version 0.51.311 contains a remote code execution vulnerability that allows authenticated attackers to execute arbitrary commands by placing malicious executable Git configuration in a workspace repository's .git/config file. Attackers can exploit Git subprocess invocations in api/workspace_git.py through…

more

vectors such as core.fsmonitor during git status, protocol.ext.allow with ext:: remotes during git fetch, credential.helper, core.askPass, core.gitProxy, or inherited environment variables including GIT_SSH_COMMAND to achieve arbitrary command execution on the host running the application.

CWE(s)
CWE-78

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
Why these techniques?

RCE in WebUI via Git command injection (CWE-78) directly enables T1190 exploitation of the public-facing app and T1059.004 Unix shell command execution.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

References