{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-18355", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-07-30T07:37:32.170Z", "datePublished": "2026-09-07T14:14:43.759Z", "dateUpdated": "2026-09-07T14:14:43.759Z"}, "containers": {"cna": {"title": "389-ds-base: 389-ds-base: heap buffer overflow via sasl wrapped-record length lower-bound underflow in sasl_io_start_packet()", "metrics": [{"other": {"content": {"value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), the wrapped-record length read from the wire is validated only against an upper bound. A small wire length (0, 1, or 2) produces an encrypted_buffer_count below the already-consumed encrypted_buffer_offset, causing an unsigned subtraction underflow in sasl_io_read_packet(). PR_Recv is then requested to read approximately 4 GiB into a 1024-byte heap buffer, resulting in a heap buffer overflow with attacker-controlled content. After a successful SASL bind with integrity protection (SSF > 0), a remote authenticated attacker can cause a denial of service or potentially achieve remote code execution. This flaw is distinct from CVE-2026-11774, whose fix only guards against upper-bound overflow."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Directory Server 11", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "redhat-ds:11/389-ds-base", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:directory_server:11"]}, {"vendor": "Red Hat", "product": "Red Hat Directory Server 12", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "redhat-ds:12/389-ds-base", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:directory_server:12"]}, {"vendor": "Red Hat", "product": "Red Hat Directory Server 13", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "389-ds-base", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:directory_server:13"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "389-ds-base", "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": "389-ds-base", "defaultStatus": "unaffected", "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": "389-ds-base", "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": "389-ds:1.4/389-ds-base", "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": "389-ds-base", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:9"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-18355", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2509186", "name": "RHBZ#2509186", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-09-07T09:00:00.000Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-191", "description": "Integer Underflow (Wrap or Wraparound)", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-191: Integer Underflow (Wrap or Wraparound)", "workarounds": [{"lang": "en", "value": "Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible."}], "timeline": [{"lang": "en", "time": "2026-07-08T00:00:00.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-09-07T09:00:00.000Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Adam Korczynski (Ada Logics), Arthur Chan (Ada Logics), David Korczynski (Ada Logics), and Team (Anthropic) for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-09-07T14:14:43.759Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

{}

{}

{}

{}