{"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\u00a0strncasecmp()\u00a0returns 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.\u00a0Affected 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"}}]}}