CVE-2026-42945

CRITICAL EPSS 99.1%
Published May 13, 20261mo ago · Modified Jun 27, 20262d ago
9.2 CVSS 4.0
Critical
Find Similar
Published May 13, 2026 1mo ago
Last Modified Jun 27, 2026 2d ago

Description

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.

CVSS Details

Base Score
9.2
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
99.1% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 2

CWE-122
CWE-131

Affected Products 13

VendorProductVersionRange
f5dos*≥4.3.0  –  ≤4.7.0
f5dos4.8.0any
f5nginx_gateway_fabric*≥1.3.0  –  ≤1.6.2
f5nginx_gateway_fabric*≥2.0.0  –  ≤2.5.1
f5nginx_ingress_controller*≥3.5.0  –  ≤3.7.2
f5nginx_ingress_controller*≥4.0.0  –  ≤4.0.1
f5nginx_ingress_controller*≥5.0.0  –  ≤5.4.1
f5nginx_instance_manager*≥2.16.0  –  ≤2.21.1
f5nginx_open_source*≥0.6.27  –  ≤1.30.0
f5nginx_plus*≥r32  –  ≤r36
f5waf*≥4.9.0  –  ≤4.16.0
f5waf*≥5.1.0  –  ≤5.8.0
f5waf*≥5.9.0  –  ≤5.12.1

References 33

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.