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Critical

NGINX map directive and regex matching vulnerability

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

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
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