{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72350", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.921Z", "datePublished": "2026-08-15T05:55:53.532Z", "dateUpdated": "2026-08-17T05:43:07.758Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:43:07.758Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_u32: reject invalid shift counts\n\nu32_match_it() executes rule-supplied shift operands on a 32-bit\nvalue. A malformed u32 rule can provide a shift count of 32 or more,\ntriggering an undefined shift out-of-bounds during packet evaluation.\n\nValidate XT_U32_LEFTSH and XT_U32_RIGHTSH operands in\nu32_mt_checkentry() and reject malformed rules before they reach the\npacket path."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - Malicious xt_u32 match rules are installed via IPT_SO_SET_REPLACE setsockopt or nftables NFNetlink (nft_compat match); per kernel CNA guidance netfilter/xtables rule setup is Local even though installed rules evaluate on ingress/egress packets through ipt_do_table.\nAC:L - The attacker fully controls XT_U32_LEFTSH/RIGHTSH shift operands (>=32) in matchinfo and can send triggering packets through the hooked netfilter chain; no race or uncontrollable victim state is required.\nPR:L - Installing xt_u32 iptables/nftables rules requires CAP_NET_ADMIN, obtainable by unprivileged users in user/network namespaces via unshare -Urn; ip_tables.c and nfnetlink enforce ns_capable/netlink_net_capable against the namespace user_ns.\nUI:N - The attacker installs the malicious u32 match rule and generates matching traffic in their namespace; no separate victim action (opening files, mounting media, clicking links) is needed.\nS:U - Undefined shift during xt_u32 packet matching and any resulting kernel crash remain within the host kernel security authority; this is standard local kernel compromise, not a VM escape or sandbox boundary crossing.\nC:H - Undefined-behavior shifts on packet-derived u32 values corrupt val and @ offset accumulation, driving attacker-influenced skb_copy_bits reads at unintended offsets; per CNA guidance exploitable kernel memory-unsafe arithmetic warrants High confidentiality.\nI:H - Invalid shift counts corrupt val/at control flow in the u32_match_it hot path; C11 undefined behavior in kernel netfilter matching is exploitable for integrity compromise and potential code execution per CNA memory-corruption guidance.\nA:H - Evaluating a malformed xt_u32 rule with shift>=32 triggers undefined shift-out-of-bounds during packet matching; vulnerable kernels also BUG() on skb_copy_bits failure, provoking kernel panic/oops during rule evaluation."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/netfilter/xt_u32.c"], "versions": [{"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "ca7c92d9701249e6daf132087756a88cbf2bb2a3", "status": "affected", "versionType": "git"}, {"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "b33b44250d57ab0e5a1e2571b5285fb0d0a7f382", "status": "affected", "versionType": "git"}, {"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "728f479dc0447ae7eaef87926ff49142e415a811", "status": "affected", "versionType": "git"}, {"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "0a8b7a6d763775709c601f584e709ae48bcc000a", "status": "affected", "versionType": "git"}, {"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "cce42014415cecd98aa49b3950e7b02ee7c81268", "status": "affected", "versionType": "git"}, {"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "a597a722fb71a534138c20359b655726622b5f17", "status": "affected", "versionType": "git"}, {"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "00d034fe8230dfc5832fe011ff2d81c1a2cc7a29", "status": "affected", "versionType": "git"}, {"version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "lessThan": "64cdf7d30ac18e43df6c48004435febb965809a8", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/netfilter/xt_u32.c"], "versions": [{"version": "2.6.23", "status": "affected"}, {"version": "0", "lessThan": "2.6.23", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "5.10.261"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "5.15.212"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "6.1.178"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "6.18.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/ca7c92d9701249e6daf132087756a88cbf2bb2a3"}, {"url": "https://git.kernel.org/stable/c/b33b44250d57ab0e5a1e2571b5285fb0d0a7f382"}, {"url": "https://git.kernel.org/stable/c/728f479dc0447ae7eaef87926ff49142e415a811"}, {"url": "https://git.kernel.org/stable/c/0a8b7a6d763775709c601f584e709ae48bcc000a"}, {"url": "https://git.kernel.org/stable/c/cce42014415cecd98aa49b3950e7b02ee7c81268"}, {"url": "https://git.kernel.org/stable/c/a597a722fb71a534138c20359b655726622b5f17"}, {"url": "https://git.kernel.org/stable/c/00d034fe8230dfc5832fe011ff2d81c1a2cc7a29"}, {"url": "https://git.kernel.org/stable/c/64cdf7d30ac18e43df6c48004435febb965809a8"}], "title": "netfilter: xt_u32: reject invalid shift counts", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/netfilter/xt_u32.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "ca7c92d9701249e6daf132087756a88cbf2bb2a3", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}, {"lessThan": "b33b44250d57ab0e5a1e2571b5285fb0d0a7f382", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}, {"lessThan": "728f479dc0447ae7eaef87926ff49142e415a811", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}, {"lessThan": "0a8b7a6d763775709c601f584e709ae48bcc000a", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}, {"lessThan": "cce42014415cecd98aa49b3950e7b02ee7c81268", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}, {"lessThan": "a597a722fb71a534138c20359b655726622b5f17", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}, {"lessThan": "00d034fe8230dfc5832fe011ff2d81c1a2cc7a29", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}, {"lessThan": "64cdf7d30ac18e43df6c48004435febb965809a8", "status": "affected", "version": "1b50b8a371e90a5e110f466e4ac02cf6b5f681de", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/netfilter/xt_u32.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.23"}, {"lessThan": "2.6.23", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.261", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.212", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.178", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_u32: reject invalid shift counts\n\nu32_match_it() executes rule-supplied shift operands on a 32-bit\nvalue. A malformed u32 rule can provide a shift count of 32 or more,\ntriggering an undefined shift out-of-bounds during packet evaluation.\n\nValidate XT_U32_LEFTSH and XT_U32_RIGHTSH operands in\nu32_mt_checkentry() and reject malformed rules before they reach the\npacket path."}], "id": "CVE-2026-72350", "lastModified": "2026-08-17T06:18:39.020", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-15T06:22:08.407", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/00d034fe8230dfc5832fe011ff2d81c1a2cc7a29"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0a8b7a6d763775709c601f584e709ae48bcc000a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/64cdf7d30ac18e43df6c48004435febb965809a8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/728f479dc0447ae7eaef87926ff49142e415a811"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a597a722fb71a534138c20359b655726622b5f17"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b33b44250d57ab0e5a1e2571b5285fb0d0a7f382"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ca7c92d9701249e6daf132087756a88cbf2bb2a3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cce42014415cecd98aa49b3950e7b02ee7c81268"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: netfilter: xt_u32: reject invalid shift counts", "id": "2516470", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516470"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-1335", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnetfilter: xt_u32: reject invalid shift counts\nu32_match_it() executes rule-supplied shift operands on a 32-bit\nvalue. A malformed u32 rule can provide a shift count of 32 or more,\ntriggering an undefined shift out-of-bounds during packet evaluation.\nValidate XT_U32_LEFTSH and XT_U32_RIGHTSH operands in\nu32_mt_checkentry() and reject malformed rules before they reach the\npacket path.", "A flaw was found in the Linux kernel's netfilter component, specifically in `xt_u32`. A local attacker with privileges to configure netfilter rules could craft a malicious `u32` rule with an invalid shift count. This could lead to an undefined shift out-of-bounds during packet evaluation, potentially causing a denial of service (DoS) or system instability."], "name": "CVE-2026-72350", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "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": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-72350\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-72350\nhttps://lore.kernel.org/linux-cve-announce/2026081512-CVE-2026-72350-e1f8@gregkh/T"], "threat_severity": "Low"}