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        "state": "PUBLISHED",
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        "dateReserved": "2026-08-27T10:38:28.793Z",
        "datePublished": "2026-09-04T09:46:06.130Z",
        "dateUpdated": "2026-10-21T20:06:18.061Z"
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    "containers": {
        "cna": {
            "title": "Corosync: corosync: integer overflow in check_memb_commit_token_sanity may bypass message length validation on 32-bit systems",
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                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "ADJACENT_NETWORK",
                        "availabilityImpact": "HIGH",
                        "baseScore": 6.5,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
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            "descriptions": [
                {
                    "lang": "en",
                    "value": "An integer overflow was found in Corosync's handling of membership commit token messages. The length-validation check for these messages can be bypassed on 32-bit systems due to an integer overflow in the calculation of the expected message length, allowing a crafted network packet to trigger an out-of-bounds memory access that crashes the Corosync daemon. This results in a denial of service for the affected cluster node. The overflow does not occur on 64-bit systems, where the length calculation is correctly performed in 64-bit arithmetic."
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                    "product": "Red Hat Enterprise Linux 10",
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                    "vendor": "Red Hat",
                    "product": "Red Hat Enterprise Linux 7",
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                    "packageName": "corosync",
                    "defaultStatus": "affected",
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                    "product": "Red Hat Enterprise Linux 8",
                    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
                    "packageName": "corosync",
                    "defaultStatus": "affected",
                    "cpes": [
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                    "vendor": "Red Hat",
                    "product": "Red Hat Enterprise Linux 9",
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                    "packageName": "corosync",
                    "defaultStatus": "affected",
                    "cpes": [
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                    "packageName": "openshift/ose-rhel-coreos-9",
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                    "packageName": "rhcos",
                    "defaultStatus": "affected",
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            ],
            "references": [
                {
                    "url": "https://access.redhat.com/security/cve/CVE-2026-81666",
                    "tags": [
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                        "x_refsource_REDHAT"
                    ]
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                    "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2524923",
                    "name": "RHBZ#2524923",
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            "datePublic": "2026-09-04T08:14:29.525Z",
            "problemTypes": [
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                    "descriptions": [
                        {
                            "cweId": "CWE-190",
                            "description": "Integer Overflow or Wraparound",
                            "lang": "en",
                            "type": "CWE"
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                    ]
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            ],
            "x_redhatCweChain": "CWE-190: Integer Overflow or Wraparound",
            "workarounds": [
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                    "lang": "en",
                    "value": "There is no complete mitigation for this vulnerability short of a fix, but the following steps reduce risk:\n\n1. Ensure cluster message authentication is enabled in corosync.conf (crypto_cipher=aes256, crypto_hash=sha256 with a shared key from corosync-keygen), which is the default when clusters are configured via 'pcs cluster setup', and disabling it (cipher=none/hash=none) is an explicitly unsupported configuration per upstream maintainer guidance.\n2. Restrict network access to the cluster communication ports (default 5405-5412/UDP) to trusted cluster node addresses only.\n3. Where architecturally feasible, prefer 64-bit deployments, since the integer overflow described here does not occur on 64-bit systems."
                }
            ],
            "timeline": [
                {
                    "lang": "en",
                    "time": "2026-08-23T00:00:00.000Z",
                    "value": "Reported to Red Hat."
                },
                {
                    "lang": "en",
                    "time": "2026-09-04T08:14:29.525Z",
                    "value": "Made public."
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Red Hat would like to thank Tristan Madani (Talence Security) for reporting this issue."
                }
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