CVE-2026-86347

MEDIUM
Published Sep 7, 2026 Modified Sep 9, 2026 CWE-400 CWE-862

Description

Affected versions of MISP allow any authenticated user to access TemplatesController::uploadFile() because the ACL entry for templates/uploadFile used the wildcard *. This bypasses the intended role restrictions applied to neighboring template-management operations. The upload handler accepts arbitrary content with only minimal checks and writes it into app/tmp/files/. A low-privileged or read-only user can therefore repeatedly upload files and consume server disk space without requiring perm_add or perm_template. The fix changes the ACL requirement from * to perm_add. The commit also rules out stronger impacts: uploaded files receive random names, path traversal/predictable overwrite is not available, the temporary directory is outside the web root, and the files are not directly served over HTTP. Therefore, the issue should not be described as arbitrary file overwrite, stored XSS, or RCE. Version affected: ≤2.5.45

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CVSS v3.1 Score

6.5
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0030
Probability of exploitation
0.23%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-400 Uncontrolled Resource Consumption
CWE-862 Missing Authorization

Affected Products

Vendor Product
misp-project misp

References

Frequently Asked Questions

What is CVE-2026-86347? +
Affected versions of MISP allow any authenticated user to access TemplatesController::uploadFile() because the ACL entry for templates/uploadFile used the wildcard *. This bypasses the intended role restrictions applied to neighboring template-management operations. The upload handler accepts arbitrary content with only minimal checks and writes it into app/tmp/files/. A low-privileged or read-only user can therefore repeatedly upload files and consume server disk space without requiring perm_add or perm_template. The fix changes the ACL requirement from * to perm_add. The commit also rules out stronger impacts: uploaded files receive random names, path traversal/predictable overwrite is not available, the temporary directory is outside the web root, and the files are not directly served over HTTP. Therefore, the issue should not be described as arbitrary file overwrite, stored XSS, or RCE. Version affected: ≤2.5.45 It has a CVSS v3.1 base score of 6.5 (MEDIUM).
How severe is CVE-2026-86347? +
CVE-2026-86347 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0030, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-86347? +
CVE-2026-86347 affects products from misp-project, specifically: misp. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-86347? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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