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High 8.1Published May 13, 2026

CVE-2026-42945NGINX ngx_http_rewrite_module vulnerability

Updated under an hour ago ()

Does this affect you?

It affects F5 NGINX Plus and 16 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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
8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-122, CWE-131
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
f5
NVD analysis
Modified
Record last updated
Sep 10, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
F5 NGINX Plus
f5:nginx_plus (from the name)
from R37 not affected; from R36 before R36 P4; from R32 before R32 P6
CNA record
F5 NGINX Open Source
f5:nginx_open_source (from the name)
from 1.31.0 not affected; from 0.6.27 before 1.30.1
CNA record
from 2:1.26.3-2.el10_1.2 not affected; from 2:1.26.3-6.el10_2.3 not affected
CISA ADP
from 2:1.26.3-1.el10_0.9 not affected
CISA ADP
from 1:1.20.1-10.el9_0.4 not affected
CISA ADP
from 1:1.20.1-16.el9_4.6 not affected
CISA ADP
from 1.30.1-1.hum1 not affected
CISA ADP
Red Hat Red Hat Openshift Data Foundation 4.14
redhat:openshift_data_foundation
from 1779972138 not affected
CISA ADP
from 1779706745 not affected
CISA ADP
from 1779798159 not affected
CISA ADP
2
CISA ADP
1
CISA ADP
f5 dos
f5:dos
from 4.3.0 through 4.7.0; 4.8.0
NVD
f5 nginx_gateway_fabric
f5:nginx_gateway_fabric
from 1.3.0 through 1.6.2; from 2.0.0 through 2.5.1
NVD
f5 nginx_ingress_controller
f5:nginx_ingress_controller
from 3.5.0 through 3.7.2; from 4.0.0 through 4.0.1; from 5.0.0 through 5.4.1
NVD
f5 nginx_instance_manager
f5:nginx_instance_manager
from 2.16.0 through 2.21.1
NVD
f5 nginx_open_source
f5:nginx_open_source
from 0.6.27 through 1.30.0
NVD
f5 nginx_plus
f5:nginx_plus
from r32 through r36
NVD
f5 waf
f5:waf
from 4.9.0 through 4.16.0; from 5.1.0 through 5.8.0; from 5.9.0 through 5.12.1
NVD

References

  • vendor-advisory, patch, mitigation
  • mitigation, technical-description, third-party-advisory
  • exploit, third-party-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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