{"api_version":"1","generated_at":"2026-04-20T17:23:10+00:00","cve":"CVE-2026-3904","urls":{"html":"https://cve.report/CVE-2026-3904","api":"https://cve.report/api/cve/CVE-2026-3904.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-3904","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-3904"},"summary":{"title":"CVE-2026-3904","description":"Calling NSS-backed functions that support caching via nscd may call the \nnscd client side code and in the GNU C Library version 2.36 under high \nload on x86_64 systems, the client may call memcmp on inputs that are \nconcurrently modified by other processes or threads and crash.\n\n\n\n\nThe nscd client in the GNU C Library uses the memcmp function with \ninputs that may be concurrently modified by another thread, potentially \nresulting in spurious cache misses, which in itself is not a security \nissue.  However in the GNU C Library version 2.36 an optimized \nimplementation of memcmp was introduced for x86_64 which could crash \nwhen invoked with such undefined behaviour, turning this into a \npotential crash of the nscd client and the application that uses it. \nThis implementation was backported to the 2.35 branch, making the nscd \nclient in that branch vulnerable as well.  Subsequently, the fix for \nthis issue was backported to all vulnerable branches in the GNU C \nLibrary repository.\n\n\nIt is advised that distributions that may have cherry-picked the memcpy \nSSE2 optimization in their copy of the GNU C Library, also apply the fix \nto avoid the potential crash in the nscd client.","state":"PUBLISHED","assigner":"glibc","published_at":"2026-03-11 14:16:30","updated_at":"2026-04-09 20:31:38"},"problem_types":["CWE-366","CWE-366 CWE-366 Race condition within a thread"],"metrics":[{"version":"3.1","source":"ADP","type":"DECLARED","score":"6.2","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":6.2,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}},{"version":"3.1","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","score":"6.2","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":6.2,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}}],"references":[{"url":"https://sourceware.org/bugzilla/show_bug.cgi?id=29863","name":"https://sourceware.org/bugzilla/show_bug.cgi?id=29863","refsource":"3ff69d7a-14f2-4f67-a097-88dee7810d18","tags":["Exploit","Issue Tracking","Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://sourceware.org/git/?p=glibc.git;a=commit;h=8804157ad9da39631703b92315460808eac86b0c","name":"https://sourceware.org/git/?p=glibc.git;a=commit;h=8804157ad9da39631703b92315460808eac86b0c","refsource":"3ff69d7a-14f2-4f67-a097-88dee7810d18","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://sourceware.org/git/?p=glibc.git;a=commit;h=b712be52645282c706a5faa038242504feb06db5","name":"https://sourceware.org/git/?p=glibc.git;a=commit;h=b712be52645282c706a5faa038242504feb06db5","refsource":"3ff69d7a-14f2-4f67-a097-88dee7810d18","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0004;hb=HEAD","name":"https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0004;hb=HEAD","refsource":"3ff69d7a-14f2-4f67-a097-88dee7810d18","tags":["Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"http://www.openwall.com/lists/oss-security/2026/03/11/5","name":"http://www.openwall.com/lists/oss-security/2026/03/11/5","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Mailing List","Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-3904","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3904","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"The GNU C Library","product":"glibc","version":"affected 2.35 2.37 custom","platforms":["x86"]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2026","cve_id":"3904","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"gnu","cpe5":"glibc","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"3904","cve":"CVE-2026-3904","epss":"0.000140000","percentile":"0.023040000","score_date":"2026-04-15","updated_at":"2026-04-16 00:13:57"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2026-03-11T15:16:39.402Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"url":"http://www.openwall.com/lists/oss-security/2026/03/11/5"}],"title":"CVE Program Container"},{"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":6.2,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}},{"other":{"content":{"id":"CVE-2026-3904","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-03-11T15:56:03.349329Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-03-11T15:56:23.027Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"defaultStatus":"unaffected","platforms":["x86"],"product":"glibc","vendor":"The GNU C Library","versions":[{"lessThan":"2.37","status":"affected","version":"2.35","versionType":"custom"}]}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<div>Calling NSS-backed functions that support caching via nscd may call the \nnscd client side code and in the GNU C Library version 2.36 under high \nload on x86_64 systems, the client may call memcmp on inputs that are \nconcurrently modified by other processes or threads and crash.</div><div><br></div><div>The nscd client in the GNU C Library uses the memcmp function with \ninputs that may be concurrently modified by another thread, potentially \nresulting in spurious cache misses, which in itself is not a security \nissue.&nbsp; However in the GNU C Library version 2.36 an optimized \nimplementation of memcmp was introduced for x86_64 which could crash \nwhen invoked with such undefined behaviour, turning this into a \npotential crash of the nscd client and the application that uses it. \nThis implementation was backported to the 2.35 branch, making the nscd \nclient in that branch vulnerable as well.&nbsp; Subsequently, the fix for \nthis issue was backported to all vulnerable branches in the GNU C \nLibrary repository.<br>\n<br>It is advised that distributions that may have cherry-picked the memcpy \nSSE2 optimization in their copy of the GNU C Library, also apply the fix \nto avoid the potential crash in the nscd client.</div>"}],"value":"Calling NSS-backed functions that support caching via nscd may call the \nnscd client side code and in the GNU C Library version 2.36 under high \nload on x86_64 systems, the client may call memcmp on inputs that are \nconcurrently modified by other processes or threads and crash.\n\n\n\n\nThe nscd client in the GNU C Library uses the memcmp function with \ninputs that may be concurrently modified by another thread, potentially \nresulting in spurious cache misses, which in itself is not a security \nissue.  However in the GNU C Library version 2.36 an optimized \nimplementation of memcmp was introduced for x86_64 which could crash \nwhen invoked with such undefined behaviour, turning this into a \npotential crash of the nscd client and the application that uses it. \nThis implementation was backported to the 2.35 branch, making the nscd \nclient in that branch vulnerable as well.  Subsequently, the fix for \nthis issue was backported to all vulnerable branches in the GNU C \nLibrary repository.\n\n\nIt is advised that distributions that may have cherry-picked the memcpy \nSSE2 optimization in their copy of the GNU C Library, also apply the fix \nto avoid the potential crash in the nscd client."}],"problemTypes":[{"descriptions":[{"cweId":"CWE-366","description":"CWE-366 Race condition within a thread","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-03-11T13:19:09.741Z","orgId":"3ff69d7a-14f2-4f67-a097-88dee7810d18","shortName":"glibc"},"references":[{"url":"https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0004;hb=HEAD"},{"url":"https://sourceware.org/bugzilla/show_bug.cgi?id=29863"},{"url":"https://sourceware.org/git/?p=glibc.git;a=commit;h=8804157ad9da39631703b92315460808eac86b0c"},{"url":"https://sourceware.org/git/?p=glibc.git;a=commit;h=b712be52645282c706a5faa038242504feb06db5"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.0"}}},"cveMetadata":{"assignerOrgId":"3ff69d7a-14f2-4f67-a097-88dee7810d18","assignerShortName":"glibc","cveId":"CVE-2026-3904","datePublished":"2026-03-11T13:19:09.741Z","dateReserved":"2026-03-10T19:52:49.054Z","dateUpdated":"2026-03-11T15:56:23.027Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-11 14:16:30","lastModifiedDate":"2026-04-09 20:31:38","problem_types":["CWE-366","CWE-366 CWE-366 Race condition within a thread"],"metrics":{"cvssMetricV31":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":6.2,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":2.5,"impactScore":3.6}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*","versionStartIncluding":"2.35","versionEndExcluding":"2.37","matchCriteriaId":"4D015406-4E4F-435F-85C8-3FC346FA1B22"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"3904","Ordinal":"1","Title":"CVE-2026-3904","CVE":"CVE-2026-3904","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"3904","Ordinal":"1","NoteData":"Calling NSS-backed functions that support caching via nscd may call the \nnscd client side code and in the GNU C Library version 2.36 under high \nload on x86_64 systems, the client may call memcmp on inputs that are \nconcurrently modified by other processes or threads and crash.\n\n\n\n\nThe nscd client in the GNU C Library uses the memcmp function with \ninputs that may be concurrently modified by another thread, potentially \nresulting in spurious cache misses, which in itself is not a security \nissue.  However in the GNU C Library version 2.36 an optimized \nimplementation of memcmp was introduced for x86_64 which could crash \nwhen invoked with such undefined behaviour, turning this into a \npotential crash of the nscd client and the application that uses it. \nThis implementation was backported to the 2.35 branch, making the nscd \nclient in that branch vulnerable as well.  Subsequently, the fix for \nthis issue was backported to all vulnerable branches in the GNU C \nLibrary repository.\n\n\nIt is advised that distributions that may have cherry-picked the memcpy \nSSE2 optimization in their copy of the GNU C Library, also apply the fix \nto avoid the potential crash in the nscd client.","Type":"Description","Title":"CVE-2026-3904"}]}}}