CVE-2026-9256
highpriority · track · 14EPSS 0.109 · 96 %ileexploit · PoCDEEURUUSEPSS · scored 2026-10-27
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when a rewrite directive uses a regex pattern with distinct, overlapping Perl-Compatible Regular Expression (PCRE) captures (for example, ^/((.*))$) and a replacement string that references multiple such captures (for example, $1$2) in a redirect or arguments context. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.1–9.2
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (4)
Public proof-of-concept and weaponised exploit code.
- 06-ux/CVE-2026-9256-POCCVE-2026-9256 Nginx heap buffer overflow POCPoC · poc_in_github
- 3nou9h/CVE-2026-9256-Poc3nou9h/CVE-2026-9256-PocPoC · poc_in_github
affected products (61)
Products and version ranges known to be affected.
advisories (5)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-1661NGINX Open Source und NGINX Plus: Schwachstelle ermöglicht Denial of Service und potenziell CodeausführungDeutsch2026-05-25csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in NGINX und NGINX NGINX Plus ausnutzen, um einen Denial of Service Angriff durchzuführen, und potenziell um beliebigen Programmcode auszuführen.
- WID-SEC-W-2026-2437Oracle Communications: Mehrere SchwachstellenDeutsch2026-07-21csaf · cert_bundDE
Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Communications ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.
- WID-SEC-W-2026-2933Splunk SOAR: Mehrere SchwachstellenDeutsch2026-08-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Splunk SOAR ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen SQL-Injection Angriff durchzuführen, um einen Cross-Site Scripting Angriff durchzuführen, und um beliebigen Programmcode auszuführen.
- BIT-nginx-2026-9256NGINX ngx_http_rewrite_module vulnerability2026-06-01vendor · osvUS
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when a rewrite directive uses a regex pattern with distinct, overlapping Perl-Compatible Regular Expression (PCRE) captures (for example, ^/((.*))$) and a replacement string that references multiple such captures (for example, $1$2) in a redirect or arguments context. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
- BIT-nginx-gateway-2026-9256NGINX ngx_http_rewrite_module vulnerability2026-06-01vendor · osvUS
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when a rewrite directive uses a regex pattern with distinct, overlapping Perl-Compatible Regular Expression (PCRE) captures (for example, ^/((.*))$) and a replacement string that references multiple such captures (for example, $1$2) in a redirect or arguments context. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
also known as (6)
Other names and identifiers for this entity.
- CNNVD-202605-4744cnnvd
- EUVD-2026-31444enisa_euvd
- BDU:2026-07182fstec_bdu
- GHSA-h78r-86c6-jgp4enisa_euvd
- BIT-nginx-2026-9256osv
- BIT-nginx-gateway-2026-9256osv
sources
Which sources assert this record, and when.
references (19)
External citations — patches, advisories, analysis.
- http://www.openwall.com/lists/oss-security/2026/05/22/14cnnvd
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-9256cnnvd
- https://my.f5.com/manage/s/article/K000161377cnnvd
- https://my.f5.com/manage/s/article/K000161377enisa_euvd
- http://www.openwall.com/lists/oss-security/2026/05/22/14Mailing Listnvd
- https://access.redhat.com/errata/RHSA-2026:20351Third Party Advisorynvd
- https://access.redhat.com/errata/RHSA-2026:28212Third Party Advisorynvd
- https://access.redhat.com/errata/RHSA-2026:28921Third Party Advisorynvd
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