CVE-2026-36760

Critical

Published: 30 April 2026

Published

30 April 2026

Modified

30 April 2026

KEV Added

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Patch

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CVSS Score v3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

EPSS Score 0.0038 30.3th percentile

Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-36760 is a critical-severity Path Traversal (CWE-22) vulnerability. Its CVSS base score is 9.6 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 30.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2026-36760 is a path traversal vulnerability (CWE-22) in the fileMd5 parameter of the /a/file/upload endpoint in JeeSite version 5.15.1. Published on 2026-04-30, it enables authenticated attackers with file upload permissions to write arbitrary files with whitelisted suffixes to arbitrary filesystem locations when chunked upload is enabled. The vulnerability has a CVSS v3.1 base score of 9.6 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N).

An authenticated attacker with file upload permissions can exploit this remotely over the network with low attack complexity and no user interaction required. By manipulating the fileMd5 parameter during chunked uploads, they can achieve path traversal, allowing them to place files with permitted suffixes anywhere on the filesystem. This results in high confidentiality and integrity impacts due to the changed scope, potentially compromising sensitive data or enabling further system abuse.

Mitigation details and discussions are available in the project's GitHub repository at https://github.com/thinkgem/jeesite and the associated issue tracker at https://github.com/thinkgem/jeesite/issues/530. Security practitioners should review these for patches, workarounds, or configuration changes, such as disabling chunked uploads.

OWASP Top 10 for Web (2025)

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-26393

Vulnerability details

An issue in the fileMd5 parameter in the /a/file/upload endpoint of JeeSite v5.15.1 allows authenticated attackers with file upload permissions to execute a path traversal and write arbitrary files with whitelisted suffixes to arbitrary filesystem locations while chunked upload is…

enabled.

CWE(s): CWE-22

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 →

T1505.003 Web Shell Persistence

Adversaries may backdoor web servers with web shells to establish persistent access to systems.

attack.mitre.org →

Why these techniques?

Path traversal in public-facing file upload endpoint enables exploitation of the web application for initial access (T1190) and direct deployment of web shells via arbitrary file write to allowed locations (T1505.003).

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