[NEW] [medium] Fortinet FortiOS and FortiProxy: Multiple vulnerabilities

mediumCVE-2026-59837 CVE-2026-23573 CVE-2026-59839

An attacker can exploit multiple vulnerabilities in Fortinet FortiOS and Fortinet FortiProxy to execute arbitrary code, conduct a Cross Site Scripting attack, and manipulate data.

CSIRTS triage

vendor: Fortinet product: FortiOS and FortiProxy Remote code execution Cross-site scriptingOther

What: Multiple vulnerabilities allow attackers to execute arbitrary code and conduct Cross Site Scripting attacks.
Who is affected: Users of Fortinet FortiOS and FortiProxy.
Urgency: Remediation is medium priority due to the potential for exploitation.
Action: Apply the latest security updates from Fortinet.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: medium
Published: 2026-07-15
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2328

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-598370.58% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 44% of all scored CVEs.
Low exploitation riskCVE-2026-235730.29% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 21% of all scored CVEs.
Low exploitation riskCVE-2026-598390.21% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 11% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-59837	coverage & exploitation status	NVD · CVE.org
CVE-2026-23573	coverage & exploitation status	NVD · CVE.org
CVE-2026-59839	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownMultiple vulnerabilities in Fortinet products (July 15, 2026)cert-fr-avis
mediumCVE-2026-59839: A improper limitation of a pathname to a restricted directory ('path traversal') vulnerability…nvd
mediumCVE-2026-59837: A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.4.0 through 7.4.1, FortiOS 7…nvd
mediumCVE-2026-23573: An Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulner…nvd
unknownStack Buffer Overflow in Log Reportfortinet
unknownPath traversal in CLI command allows deletion of root file systemfortinet
unknownSSL-VPN Reflected XSSfortinet