CVE-2026-42533

🗓️ 15 Jul 2026 14:33:45Reported by f5Type

cve🔗 web.nvd.nist.gov📰️ 15 Media mentions👁 238 Views🌐 WEB

NGINX map directive regex can cause heap overflow, DoS, or code execution via crafted requests.

Reporter	Title	Published	Views	Family All 87
GithubExploit	Exploit for CVE-2026-42533	4 Jul 202611:05	–	githubexploit
GithubExploit	Exploit for Incorrect Authorization in F5 Nginx_Plus	28 Jul 202607:29	–	githubexploit
GithubExploit	Exploit for CVE-2026-42533	22 Jul 202612:48	–	githubexploit
GithubExploit	Exploit for CVE-2026-42533	27 Jul 202608:03	–	githubexploit
FreeBSD	Angie -- multiple vulnerabilities	17 Jul 202600:00	–	freebsd
FreeBSD	nginx -- multiple vulnerabilities	15 Jul 202600:00	–	freebsd
Amazon	Important: nginx	4 Aug 202600:00	–	amazon
Amazon	Important: nginx	4 Aug 202600:00	–	amazon
AlpineLinux	CVE-2026-42533	15 Jul 202614:33	–	alpinelinux
Information Security Automation	Июльский Linux Patch Wednesday	31 Jul 202616:00	–	avleonov

[
  {
    "vendor": "F5",
    "product": "NGINX Plus",
    "modules": [
      "map directive with regex matching"
    ],
    "versions": [
      {
        "status": "affected",
        "version": "37.0.0.1",
        "lessThan": "37.0.3.1",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "R36",
        "lessThan": "R36 P7",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "R33",
        "lessThan": "*",
        "versionType": "custom"
      }
    ],
    "defaultStatus": "unknown"
  },
  {
    "vendor": "F5",
    "product": "NGINX Open Source",
    "modules": [
      "map directive with regex matching"
    ],
    "versions": [
      {
        "status": "affected",
        "version": "1.31.2",
        "lessThan": "1.31.3",
        "versionType": "custom"
      },
      {
        "status": "affected",
        "version": "0.9.6",
        "lessThan": "1.30.4",
        "versionType": "custom"
      }
    ],
    "defaultStatus": "unknown"
  }
]

Source	Link
my	www.my.f5.com/manage/s/article/K000162097

Parameter	Position	Path	Description	CWE
$1	path	/api/(...)	Vulnerable two-pass map/regex capture interaction on /api/(...) allowing out-of-bounds write via captured $1 and overflow gadget in a pre-auth RCE scenario.	CWE-122
$overflow_gadget	path	/api/(...)	Vulnerable two-pass map/regex capture interaction on /api/(...) allowing out-of-bounds write via captured $1 and overflow gadget in a pre-auth RCE scenario.	CWE-122

29 Jul 2026 05:16Current

6.4Medium risk

Vulners AI Score6.4

CVSS 3.18.1

CVSS 49.2

EPSS0.03596

SSVC

CWE-122