NGINX is a widely deployed web server/proxy; remote DoS and potential RCE at CVSS 9.2 can disrupt many organizations and merits broad notification.
CVE-2026-15176
Heap overflow in NGINX via alias+rewrite or $request_filename leading to DoS and possible RCE
Is CVE-2026-15176 being exploited?
Not confirmed. CVE-2026-15176 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-15176?
CVE-2026-15176 is rated Critical with a CVSS score of 9.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-15176?
Not known from our data. No patch reference has been recorded for CVE-2026-15176, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-15176 affect?
CVE-2026-15176 affects NGINX Open Source, NGINX Plus, NGINX worker processes. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-15176?
Audit/remove alias+rewrite using $request_filename, restrict exposure behind WAF, and apply vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote crafted HTTP requests can trigger a heap buffer overflow causing worker crash (DoS) and may enable remote code execution when ASLR is disabled or bypassed.
Immediate action required
- affected>= 1.31.0 and < 1.31.7
- affected>= 0.1.29 and < 1.30.6
- affected>= 37.1.0 and < 37.1.0.1
- affected>= 37.0.0 and < 37.0.5.1
- affected>= R36 and < *
- affected>= R35 and < *
- affected>= R34 and < *
- affected>= R33 and < *
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.