NGINX map directive and regex matching vulnerability
A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and the root directive or access log format references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. 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. Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
CVE-2026-93479
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-93479
NGINX Plus
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
NGINX Open Source
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "F5",
"modules": [
"The map directive with regex matching"
],
"product": "NGINX Plus",
"versions": [
{
"status": "affected",
"version": "37.1.0",
"lessThan": "37.1.0.1",
"versionType": "custom"
},
{
"status": "affected",
"version": "37.0.0",
"lessThan": "37.0.5.1",
"versionType": "custom"
},
{
"status": "affected",
"version": "R36",
"lessThan": "*",
"versionType": "custom"
},
{
"status": "affected",
"version": "R35",
"lessThan": "*",
"versionType": "custom"
},
{
"status": "affected",
"version": "R34",
"lessThan": "*",
"versionType": "custom"
},
{
"status": "affected",
"version": "R33",
"lessThan": "*",
"versionType": "custom"
}
],
"defaultStatus": "unknown"
},
{
"vendor": "F5",
"modules": [
"The map directive with regex matching"
],
"product": "NGINX Open Source",
"versions": [
{
"status": "affected",
"version": "1.31.2",
"lessThan": "1.31.7",
"versionType": "custom"
},
{
"status": "affected",
"version": "1.30.0",
"lessThan": "1.30.6",
"versionType": "custom"
}
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-93479
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #53295 · Revision 1
- Added to Heist Feed
- Publisher date