nginx — security advisory
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.
- Products
- nginx
- Affected versions
- 1.22.1-9, 1.22.1-9+deb12u1, 1.22.1-9+deb12u2, 1.22.1-9+deb12u3, 1.22.1-9+deb12u4, 1.22.1-9+deb12u5, 1.22.1-9+deb12u6, 1.26.3-3, 1.26.3-3+deb13u1, 1.26.3-3+deb13u2, 1.26.3-3+deb13u3, 1.26.3-3+deb13u4, 1.28.0-1, 1.28.0-2, 1.28.0-3, 1.28.0-4, 1.28.0-5, 1.28.0-6, 1.28.1-1, 1.28.1-2, 1.28.1-3, 1.28.2-1, 1.28.2-2, 1.28.2-3, 1.28.2-4, 1.28.3-1, 1.28.3-2, 1.30.0-1, 1.30.0-2
- Fixed versions
- 1.22.1-9+deb12u7, 1.26.3-3+deb13u5, 1.30.0-3
- CVEs
- CVE-2026-42945
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 17:46 UTC · Revision 2
Source evidence
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.
osv:DEBIAN-CVE-2026-42945
nginx
Fixed versions: 1.22.1-9+deb12u7
nginx
Fixed versions: 1.26.3-3+deb13u5
nginx
Fixed versions: 1.30.0-3
Complete source record
{
"id": "b542098b5ea44a60ea3a5ae20f980183fad437d4f553758303e6615bac8ab72f",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-42945",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-42945",
"summary": "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.",
"evidence": "osv:DEBIAN-CVE-2026-42945",
"products": [
{
"name": {
"value": "nginx",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.22.1-9+deb12u7",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "1.22.1-9",
"evidence": "/affected/0/versions"
},
{
"value": "1.22.1-9+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "1.22.1-9+deb12u2",
"evidence": "/affected/0/versions"
},
{
"value": "1.22.1-9+deb12u3",
"evidence": "/affected/0/versions"
},
{
"value": "1.22.1-9+deb12u4",
"evidence": "/affected/0/versions"
},
{
"value": "1.22.1-9+deb12u5",
"evidence": "/affected/0/versions"
},
{
"value": "1.22.1-9+deb12u6",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "nginx",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.26.3-3+deb13u5",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "1.26.3-3",
"evidence": "/affected/1/versions"
},
{
"value": "1.26.3-3+deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "1.26.3-3+deb13u2",
"evidence": "/affected/1/versions"
},
{
"value": "1.26.3-3+deb13u3",
"evidence": "/affected/1/versions"
},
{
"value": "1.26.3-3+deb13u4",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "nginx",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.30.0-3",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "1.26.3-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.0-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.0-4",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.0-5",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.0-6",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.1-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.1-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.2-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.2-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.2-4",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.3-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.28.3-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.30.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.30.0-2",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "critical",
"structured": {
"id": "DEBIAN-CVE-2026-42945",
"aliases": [
"DEBIAN-CVE-2026-42945"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "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"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.22.1-9+deb12u7"
}
]
}
],
"package": {
"name": "nginx",
"purl": "pkg:deb/debian/nginx?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1.22.1-9",
"1.22.1-9+deb12u1",
"1.22.1-9+deb12u2",
"1.22.1-9+deb12u3",
"1.22.1-9+deb12u4",
"1.22.1-9+deb12u5",
"1.22.1-9+deb12u6"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42945.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.26.3-3+deb13u5"
}
]
}
],
"package": {
"name": "nginx",
"purl": "pkg:deb/debian/nginx?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.26.3-3",
"1.26.3-3+deb13u1",
"1.26.3-3+deb13u2",
"1.26.3-3+deb13u3",
"1.26.3-3+deb13u4"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42945.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.30.0-3"
}
]
}
],
"package": {
"name": "nginx",
"purl": "pkg:deb/debian/nginx?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.26.3-3",
"1.28.0-1",
"1.28.0-2",
"1.28.0-3",
"1.28.0-4",
"1.28.0-5",
"1.28.0-6",
"1.28.1-1",
"1.28.1-2",
"1.28.1-3",
"1.28.2-1",
"1.28.2-2",
"1.28.2-3",
"1.28.2-4",
"1.28.3-1",
"1.28.3-2",
"1.30.0-1",
"1.30.0-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42945.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-27T09:47:35.317495074Z",
"provider": "osv",
"upstream": [
"CVE-2026-42945"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-42945"
]
},
"related_cves": [
{
"value": "CVE-2026-42945",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 461174,
"published_at": "2026-05-13T16:16:50.19+00:00"
}