Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-05-15 08:50

Modified

2026-09-08 08:34

Summary

NGINX ngx_http_charset_module vulnerability

Details

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When charset, source_charset, and charset_map and proxy_pass with disabled buffering ("off") directives are configured, unauthenticated attackers can send requests that with conditions beyond the attackers' control to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.

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

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "nginx",
        "purl": "pkg:bitnami/nginx"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.3.50"
            },
            {
              "fixed": "1.30.1"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/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"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42934"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When charset, source_charset, and charset_map\u00a0and proxy_pass\u00a0with disabled buffering (\"off\") directives are configured, unauthenticated attackers can send requests that with conditions beyond the attackers\u0027 control to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.\n\n\n\n\u00a0Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
  "id": "BIT-nginx-2026-42934",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-05-15T08:50:06.374Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://my.f5.com/manage/s/article/K000161028"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42934"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "NGINX ngx_http_charset_module vulnerability"
}

CVE-2026-42934 (GCVE-0-2026-42934)

Vulnerability from cvelistv5 – Published: 2026-05-13 14:12 – Updated: 2026-06-08 20:34

Title

NGINX ngx_http_charset_module vulnerability

Summary

Severity

4.8 (Medium)


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

6.3 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-13 15:55 UTC

CWE

CWE-125 - Out-of-bounds Read

Assigner

f5 mitre root

References

1 reference

URL	Tags
https://my.f5.com/manage/s/article/K000161028	vendor-advisorypatch

Impacted products

2 products

Vendor	Product	Version
F5	NGINX Plus	Unaffected: R37 , < * (custom) Affected: R36 , < R36 P4 (custom) Affected: R32 , < R32 P6 (custom)
F5	NGINX Open Source	Unaffected: 1.31.0 , < * (semver) Affected: 0.3.50 , < 1.30.1 (semver)

Date Public

2026-05-13 14:00

Credits

F5 acknowledges David Carlier, Zhenpeng (Leo) Lin of depthfirst, and GAO Liyou for bringing this issue to our attention and following the highest standards of coordinated disclosure.

Show details on NVD website

JSON

To clipboard

{
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    "adp": [
      {
        "metrics": [
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                "id": "CVE-2026-42934",
                "options": [
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                    "Exploitation": "none"
                  },
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                  },
                  {
                    "Technical Impact": "partial"
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                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-13T15:55:18.483975Z",
                "version": "2.0.3"
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          "shortName": "CISA-ADP"
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          "modules": [
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          ],
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        {
          "defaultStatus": "unaffected",
          "modules": [
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          ],
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          "vendor": "F5",
          "versions": [
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              "status": "unaffected",
              "version": "1.31.0",
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            },
            {
              "lessThan": "1.30.1",
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      "descriptions": [
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              "value": "\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\n\n\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eNGINX Plus and NGINX Open Source have a vulnerability in the \u003c/span\u003e\u003cstrong\u003engx_http_charset_module \u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003emodule. When \u003c/span\u003e\u003cstrong\u003echarset\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e, \u003c/span\u003e\u003cstrong\u003esource_charset\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e, and \u003c/span\u003e\u003cstrong\u003echarset_map\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u0026nbsp;and \u003c/span\u003e\u003cstrong\u003eproxy_pass\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u0026nbsp;with disabled buffering (\"off\") directives are configured, unauthenticated attackers can send requests that with conditions beyond the attackers\u0027 control to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.\u003c/span\u003e\n\n\u003c/span\u003e\n\n\u0026nbsp;Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
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        }
      ],
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            "confidentialityImpact": "LOW",
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            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
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            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
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            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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      "source": {
        "discovery": "EXTERNAL"
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      "title": "NGINX ngx_http_charset_module vulnerability",
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    "assignerShortName": "f5",
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    "datePublished": "2026-05-13T14:12:44.331Z",
    "dateReserved": "2026-04-30T23:04:27.960Z",
    "dateUpdated": "2026-06-08T20:34:05.147Z",
    "state": "PUBLISHED"
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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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.