{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42934","assignerOrgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","state":"PUBLISHED","assignerShortName":"f5","dateReserved":"2026-04-30T23:04:27.960Z","datePublished":"2026-05-13T14:12:44.331Z","dateUpdated":"2026-06-08T20:34:05.147Z"},"containers":{"cna":{"providerMetadata":{"orgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","shortName":"f5","dateUpdated":"2026-06-08T20:34:05.147Z"},"title":"NGINX ngx_http_charset_module vulnerability","datePublic":"2026-05-13T14:00:00.000Z","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-125","description":"CWE-125 Out-of-bounds Read","type":"CWE"}]}],"affected":[{"vendor":"F5","product":"NGINX Plus","modules":["ngx_http_charset_module"],"versions":[{"status":"unaffected","version":"R37","lessThan":"*","versionType":"custom"},{"status":"affected","version":"R36","lessThan":"R36 P4","versionType":"custom"},{"status":"affected","version":"R32","lessThan":"R32 P6","versionType":"custom"}],"defaultStatus":"unknown"},{"vendor":"F5","product":"NGINX Open Source","modules":["ngx_http_charset_module"],"versions":[{"status":"unaffected","version":"1.31.0","lessThan":"*","versionType":"semver"},{"status":"affected","version":"0.3.50","lessThan":"1.30.1","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"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.\n\n\n\n Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.","supportingMedia":[{"type":"text/html","base64":false,"value":"<span style=\"background-color: rgb(255, 255, 255);\">\n\n<span style=\"background-color: rgb(255, 255, 255);\">NGINX Plus and NGINX Open Source have a vulnerability in the </span><strong>ngx_http_charset_module </strong><span style=\"background-color: rgb(255, 255, 255);\">module. When </span><strong>charset</strong><span style=\"background-color: rgb(255, 255, 255);\">, </span><strong>source_charset</strong><span style=\"background-color: rgb(255, 255, 255);\">, and </span><strong>charset_map</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;and </span><strong>proxy_pass</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;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.</span>\n\n</span>\n\n&nbsp;Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}]}],"references":[{"url":"https://my.f5.com/manage/s/article/K000161028","tags":["vendor-advisory","patch"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"LOW","baseSeverity":"MEDIUM","baseScore":4.8,"vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"version":"4.0","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subAvailabilityImpact":"NONE","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","baseSeverity":"MEDIUM","baseScore":6.3,"vectorString":"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"}}],"credits":[{"lang":"en","value":"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.","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"F5 SIRTBot v1.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-13T15:55:18.483975Z","id":"CVE-2026-42934","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-13T16:07:10.334Z"}}]}}