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The subsequent get_len() call then dereferences\n*bs->cur++, reading 1 byte past the end of the buffer. If that byte\nhas bit 7 set, get_len() reads a second byte as well.\n\nThis can be triggered remotely by sending a crafted Q.931 SETUP message\nwith a User-User Information Element containing exactly 2 bytes of\nPER-encoded data ({0x08, 0x00}) to port 1720 through a firewall with\nthe nf_conntrack_h323 helper active. The decoder fully consumes the\nPER buffer before reaching this code path, resulting in a 1-2 byte\nheap-buffer-overflow read confirmed by AddressSanitizer.\n\nFix this by checking for 2 bytes (the maximum that get_len() may read)\ninstead of the uninitialized `len`. This matches the pattern used at\nevery other get_len() call site in the same file, where the caller\nchecks for 2 bytes of available data before calling get_len()."}], "id": "CVE-2026-43233", "lastModified": "2026-05-12T19:03:56.650", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.2, "baseSeverity": "HIGH", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 4.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-05-06T12:16:43.417", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2a3aac4205e7d2f1aca2e3827de8cdd517d36c4a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/35f1943d242e1b9f0b6e91c0c93bfb293a9f8224"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/53d32735d77ab56cc3fc7bd53a7d099418f19be1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/7ef82863d42261817a6394c6c881bd6757a70f16"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/81f2fc5b0d0cf4696146f00f837596d10b92dead"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/baed0d9ba91d4f390da12d5039128ee897253d60"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/bcb50aa0b8f2b74a9fe5a1c7bee6f2657a288041"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/f0a83d0a4b7c127d32ac06d607a9214937716129"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: netfilter: nf_conntrack_h323: fix OOB read in decode_choice()", "id": "2467135", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2467135"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-131", "details": ["A flaw was found in the Linux kernel's `nf_conntrack_h323` helper. A remote attacker could exploit this by sending a specially crafted Q.931 SETUP message to port 1720 through a firewall with the `nf_conntrack_h323` helper active. This memory corruption vulnerability leads to an out-of-bounds read, which can result in a heap-buffer-overflow."], "name": "CVE-2026-43233", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-05-06T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-43233\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-43233\nhttps://lore.kernel.org/linux-cve-announce/2026050657-CVE-2026-43233-e6b4@gregkh/T"], "threat_severity": "Moderate"}

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