CVE-2026-9256

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.

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.

NGINX is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server.

Security Fix(es):

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.(CVE-2026-9256)

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Root has patched CVE-2026-9256 in the rootio-nginx package for Root:Debian:11. Multiple fixed versions available.

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.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: ngx_http_rewrite_module: code execution and denial of service (CVE-2026-9256)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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.

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.

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.

• SECURITY UPDATE: heap buffer overflow in ngx_http_rewrite_module with overlapping captures
  • debian/patches/CVE-2026-9256.patch: fix heap buffer overflow in ngx_http_script_regex_start_code() when a rewrite replacement string with no variables has overlapping captures, by moving the per-capture length accumulation and ngx_escape_uri() call inside a single loop over the actual captures buffer.
  • CVE-2026-9256

• CVE-2026-9256: heap buffer overflow in ngx_http_script_regex_start_code() when a rewrite replacement contains overlapping captures with the redirect parameter or argument string; the per-capture length accumulation is refactored to also account for escape-uri expansion per capture region, preventing under-allocation of the rewrite output buffer

• CVE-2026-9256: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures

• CVE-2026-9256: fix heap buffer overflow with overlapping captures in ngx_http_rewrite_module

• CVE-2026-9256: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures

• SECURITY UPDATE: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures
  • debian/patches/CVE-2026-9256.patch: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures
  • CVE-2026-9256

• SECURITY UPDATE: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures
  • debian/patches/CVE-2026-9256.patch: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures
  • CVE-2026-9256

• CVE-2026-9256: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures

• CVE-2026-9256: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures

• CVE-2026-9256: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures

• CVE-2026-9256: fix heap buffer overflow with overlapping captures in ngx_http_rewrite_module

• SECURITY UPDATE: Heap buffer overflow in ngx_http_rewrite_module via overlapping PCRE captures in replacement strings
  • debian/patches/CVE-2026-9256.patch: recompute buffer length per capture (including escaping) in ngx_http_script_regex_start_code to prevent buffer overrun when redirect parameter is used or arguments appear in the rewrite replacement string
  • CVE-2026-9256

• CVE-2026-9256: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures

• CVE-2026-9256: fix heap buffer overflow in ngx_http_rewrite_module with overlapping captures

The updated package fixes a security vulnerability: NGINX ngx_http_rewrite_module vulnerability. (CVE-2026-9256)

These are all security issues fixed in the nginx-1.31.1-1.1 package on the GA media of openSUSE Tumbleweed.

This update for nginx fixes the following issue

• CVE-2026-9256: heap buffer overflow in the ngx_http_rewrite_module when using a configuration with overlapping captures (bsc#1266215).

This update for nginx fixes the following issue

• CVE-2026-9256: heap buffer overflow in the ngx_http_rewrite_module when using a configuration with overlapping captures (bsc#1266215).

This update for nginx fixes the following issue

• CVE-2026-9256: heap buffer overflow in the ngx_http_rewrite_module when using a configuration with overlapping captures (bsc#1266215).

This update for nginx fixes the following issues

• CVE-2026-9256: heap buffer overflow in the ngx_http_rewrite_module when using a configuration with overlapping captures (bsc#1266215).
• CVE-2026-27651: denial of service via undisclosed requests when the ngx_mail_auth_http_module is enabled (bsc#1260415).
• CVE-2026-32647: NGINX worker memory over-read or over-write via a specially crafted MP4 file (bsc#1260420).
• CVE-2026-40701: heap use-after-free in the worker process when the ssl_verify_client and the ssl_ocsp directives are set due to issue in the ngx_http_ssl_module module (bsc#1265229).
• CVE-2026-42934: heap buffer overread in the worker process due to issue in the ngx_http_charset_module module (bsc#1265231).
• CVE-2026-42945: heap buffer overflow via crafted HTTP requests due to issue in ngx_http_rewrite_module (bsc#1265232).
• CVE-2026-42946: excessive memory allocation and data overread due to issue in the ngx_http_scgi_module and ngx_http_uwsgi_module modules (bsc#1265233).