Broad impact on NGINX JS users; unauthenticated heap overflow can crash or, on ASLR-disabled systems, enable code execution.
CVE-2026-8711
Unauthenticated heap overflow in NGINX JS fetch; may lead to code execution on ASLR-disabled systems.
Is CVE-2026-8711 being exploited?
Not confirmed. CVE-2026-8711 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 9.7% probability of exploitation in the next 30 days.
How severe is CVE-2026-8711?
CVE-2026-8711 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-2026-8711?
Yes. A fix has been recorded for CVE-2026-8711. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-8711 affect?
CVE-2026-8711 affects NGINX JS module (nginx-js) with js_fetch_proxy usage. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-8711?
Patch when available; disable/restrict js_fetch_proxy if possible
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote unauthenticated exploit; heap overflow via crafted HTTP requests; code execution possible if ASLR is disabled.
Immediate action required
- affected>= 0.9.4 and < 0.9.9
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.