CVE-2026-42945: dos vulnerability

CVE-2026-42945: critical vulnerability affecting dos. Check CVSS, KEV status, business impact and recommended administrator actions.
CVE-2026-42945CVSS 9.2Web

CVE-2026-42945: dos vulnerability

CVE-2026-42945: critical vulnerability affecting dos. Check CVSS, KEV status, business impact and recommended administrator actions.

CVSS
9.2 CRITICAL
EPSS
99.08%
Known exploited
not in KEV
Product
dos

What is known

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 Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its 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.

Business impact

Successful exploitation of CVE-2026-42945, a critical vulnerability (CVSS 9.2) affecting dos, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether dos is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

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