{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-6104","assignerOrgId":"dd77f84a-d19a-4638-8c3d-a322d820ed2b","state":"PUBLISHED","assignerShortName":"php","dateReserved":"2026-04-11T04:15:03.938Z","datePublished":"2026-05-10T04:35:17.328Z","dateUpdated":"2026-05-11T13:04:58.462Z"},"containers":{"cna":{"providerMetadata":{"orgId":"dd77f84a-d19a-4638-8c3d-a322d820ed2b","shortName":"php","dateUpdated":"2026-05-10T04:35:17.328Z"},"title":"Global buffer over-read in mb_convert_encoding() with attacker-supplied encoding","datePublic":"2026-05-07T00:00:00.000Z","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-125","description":"CWE-125 Out-of-bounds Read","type":"CWE"}]}],"affected":[{"vendor":"PHP Group","product":"PHP","packageName":"mbstring","versions":[{"status":"affected","version":"8.4.*","lessThan":"8.4.21","versionType":"semver"},{"status":"affected","version":"8.5.*","lessThan":"8.5.6","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.","supportingMedia":[{"type":"text/html","base64":false,"value":"In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to <code>mb_convert_encoding()</code> or related mbstring functions, the code incorrectly assumes that when&nbsp;<code>strncasecmp()</code>&nbsp;returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash.<span>&nbsp;Affected functions include </span><code>mb_convert_encoding()</code><span>, </span><code>mb_detect_encoding()</code><span>, </span><code>mb_convert_variables()</code><span>, and </span><code>mb_detect_order()</code><span>, as well as the </span><code>mbstring.detect_order</code><span> and </span><code>mbstring.http_output</code><span> INI settings.</span>"}]}],"references":[{"url":"https://github.com/php/php-src/security/advisories/GHSA-74r9-qxhc-fx53","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","subConfidentialityImpact":"LOW","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subAvailabilityImpact":"LOW","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"MODERATE","providerUrgency":"AMBER","version":"4.0","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:L/SI:N/SA:L/RE:M/U:Amber"}}],"credits":[{"lang":"en","value":"Akshay Jain","type":"reporter"},{"lang":"en","value":"Ilija Tovilo","type":"remediation developer"}],"source":{"advisory":"GHSA-74r9-qxhc-fx53","discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-11T13:04:44.572023Z","id":"CVE-2026-6104","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"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":"2026-05-11T13:04:58.462Z"}}]}}