{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-11850", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-06-10T08:12:34.560Z", "datePublished": "2026-06-11T09:49:07.726Z", "dateUpdated": "2026-06-11T09:49:07.726Z"}, "containers": {"cna": {"title": "Krb5: krb5: integer underflow in berval2tl_data() leads to heap out-of-bounds read", "metrics": [{"other": {"content": {"value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "An integer underflow vulnerability was found in MIT krb5 in the berval2tl_data() function in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c. The function performs an unsigned subtraction (bv_len - 2) without a prior bounds check. When bv_len is 0 or 1, the subtraction wraps to a large value which is then truncated to uint16_t, yielding 0xFFFE (65534) or 0xFFFF (65535). The subsequent malloc succeeds and memcpy reads up to 65534 bytes from a 0-1 byte buffer, resulting in a heap out-of-bounds read.\nThe attack vector involves a malicious or compromised LDAP KDB backend returning a krbExtraData attribute with bv_len < 2, triggering the underflow when the KDC or kadmind reads principal data."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "krb5", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:10"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 6", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "krb5", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:6"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "krb5", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:7"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "krb5", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:8"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "krb5", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:9"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "krb5", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rhcos", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:openshift:4"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-11850", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2459970", "name": "RHBZ#2459970", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-04-21T00:00:00.000Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-191", "description": "Integer Underflow (Wrap or Wraparound)", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-191: Integer Underflow (Wrap or Wraparound)", "timeline": [{"lang": "en", "time": "2026-04-21T00:00:00.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-04-21T00:00:00.000Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Sebasti\u00e1n Alba Vives for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-06-11T09:49:07.726Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "An integer underflow vulnerability was found in MIT krb5 in the berval2tl_data() function in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c. The function performs an unsigned subtraction (bv_len - 2) without a prior bounds check. When bv_len is 0 or 1, the subtraction wraps to a large value which is then truncated to uint16_t, yielding 0xFFFE (65534) or 0xFFFF (65535). The subsequent malloc succeeds and memcpy reads up to 65534 bytes from a 0-1 byte buffer, resulting in a heap out-of-bounds read.\nThe attack vector involves a malicious or compromised LDAP KDB backend returning a krbExtraData attribute with bv_len < 2, triggering the underflow when the KDC or kadmind reads principal data."}], "id": "CVE-2026-11850", "lastModified": "2026-06-11T10:16:21.217", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.0, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 0.7, "impactScore": 4.2, "source": "secalert@redhat.com", "type": "Primary"}]}, "published": "2026-06-11T10:16:21.217", "references": [{"source": "secalert@redhat.com", "url": "https://access.redhat.com/security/cve/CVE-2026-11850"}, {"source": "secalert@redhat.com", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2459970"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-191"}], "source": "secalert@redhat.com", "type": "Primary"}]}

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