Arbitrary file upload in Emlog
CVE-2026-22799
Emlog is an open source website building system. emlog v2.6.1 and earlier exposes a REST API endpoint (/index.php?rest-api=upload) for media file uploads. The endpoint fails to implement proper validation of file types, extensions, and content, allowing authenticated attackers (with a valid API key or admin session cookie) to upload arbitrary files (including malicious PHP scripts) to the server. An attacker can obtain the API key either by gaining administrator access to enable the REST API setting, or via information disclosure vulnerabilities in the application. Once uploaded, the malicious PHP file can be executed to gain remote code execution (RCE) on the target server, leading to full server compromise.
Vulnerability class: Unrestricted File Upload
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (52.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.001
Affected products
- Emlog — versions <= 2.6.1
Weakness classification (CWE)
References
- github.com/emlog/emlog/security/advisories/GHSA-p837-mrw9-5x5j (Exploit, Vendor Advisory)
- github.com/emlog/emlog/commit/429b02fda842254b9b9b39303e9161999c180560 (Patch)
Frequently asked questions
- What is CVE-2026-22799?
- CVE-2026-22799 is a high-severity vulnerability in Emlog, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2026-01-12.
- How severe is CVE-2026-22799?
- High severity. CVSS v3 base score is 8.8 out of 10.