Buffer overflow in F5 Nginx Open Source
CVE-2026-42945
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Express…
Vulnerability class: Buffer Overflow
EPSS: 0.009 (76.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- F5 Nginx Open Source — versions 1.31.0, 0.6.27
- F5 Nginx Plus — versions R37, R36, R32
Weakness classification (CWE)
Public proof-of-concept exploits
- DepthFirstDisclosures/Nginx-Rift
- cipherspy/CVE-2026-42945-POC
- friparia/NGINX_RIFT_SCAN_CVE_2026_42945
- oseasfr/Scanner_CVE_2026-42945
- rheodev/CVE-2026-42945
- p3Nt3st3r-sTAr/CVE-2026-42945-POC
- MateusVerass/nGixshell
- nu0l/NGINX-Rift
- bamov970/CVE-2026-42945-Nginx-RCE-bypass-ASLR
- strivepan/Nginx_cve-2026-42945-scanner-gui
References
- f5sirt@f5.com (vendor-advisory, patch)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2026-42945?
- CVE-2026-42945 is a high-severity vulnerability in F5 Nginx Open Source, classified under Heap-based Buffer Overflow. CVSS score: 8.1/10. Published 2026-05-13.
- How severe is CVE-2026-42945?
- High severity. CVSS v3 base score is 8.1 out of 10.
- Is CVE-2026-42945 known to be exploited?
- 44 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.