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GHSA-PJ32-6RXC-GCMQ

Vulnerability from github – Published: 2026-05-19 15:31 – Updated: 2026-05-21 21:30

Details

NGINX JavaScript has a vulnerability when the js_fetch_proxy directive is configured with at least one client-controlled NGINX variable (for example, $http_, $arg_, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker 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, for systems with Address Space Layout Randomization (ASLR) disabled, code execution is possible.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Severity

8.1 (High)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

9.2 (Critical)


                  
                    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-8711"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-19T15:16:33Z",
    "severity": "CRITICAL"
  },
  "details": "NGINX JavaScript has a vulnerability when the js_fetch_proxy\u00a0directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker 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, for systems with Address Space Layout Randomization (ASLR) disabled, code execution is possible. \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
  "id": "GHSA-pj32-6rxc-gcmq",
  "modified": "2026-05-21T21:30:31Z",
  "published": "2026-05-19T15:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-8711"
    },
    {
      "type": "WEB",
      "url": "https://my.f5.com/manage/s/article/K000161307"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-8711 (GCVE-0-2026-8711)

Vulnerability from cvelistv5 – Published: 2026-05-19 14:04 – Updated: 2026-05-21 18:29 X_F5

Title

NGINX JavaScript vulnerability

Summary

NGINX JavaScript has a vulnerability when the js_fetch_proxy directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker 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.

Severity

8.1 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

9.2 (Critical)


                        
                          CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

References

1 reference

URL	Tags
https://my.f5.com/manage/s/article/K000161307	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
F5	NGINX JavaScript	Affected: 0.9.4 , < 0.9.9 (custom)

Date Public

2026-05-19 14:00

Credits

"F5 acknowledges udolemi (S2W) for bringing this issue to our attention and following the highest standards of coordinated disclosure."

Show details on NVD website

JSON

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  "containers": {
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      {
        "metrics": [
          {
            "other": {
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                "id": "CVE-2026-8711",
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                  },
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                "timestamp": "2026-05-19T00:00:00+00:00",
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        },
        "title": "CISA ADP Vulnrichment"
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    "cna": {
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          ],
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          "versions": [
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        }
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      "descriptions": [
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        "discovery": "EXTERNAL"
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      "title": "NGINX JavaScript vulnerability",
      "x_generator": {
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-PJ32-6RXC-GCMQ

CVE-2026-8711 (GCVE-0-2026-8711)

Tags

Sightings

Nomenclature