{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46323","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-13T15:03:33.112Z","datePublished":"2026-06-09T12:11:15.562Z","dateUpdated":"2026-08-25T12:05:36.169Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:31:18.394Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gro: don't merge zcopy skbs\n\nskb_gro_receive() can currently copy frags between the source and GRO\nskb, without checking the zerocopy status, and in particular the\nSKBFL_MANAGED_FRAG_REFS flag.\n\nWhen SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference\non the pages in shinfo->frags. Appending those frags to another skb's\nfrags without fixing up the page refcount can lead to UAF.\n\nWhen either the last skb in the GRO chain (the one we would append\nfrags to) or the source skb is zerocopy, don't merge the skbs."}],"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 - Exploitation requires a local attacker to inject zerocopy/managed-frags skbs via io_uring SEND_ZC, TUN/TAP, or similar local APIs; ordinary remote wire packets processed by GRO do not carry SKBFL_MANAGED_FRAG_REFS, so a network-only attacker cannot reach the buggy merge path.\nAC:L - The attacker fully controls both sides of the GRO merge (seed and zerocopy TCP segments over a veth pair), timing (netem delay, RST race), and buffer setup; a public working LPE exploit exists, so success does not depend on conditions outside attacker control.\nPR:L - Triggering requires only a basic unprivileged local account with io_uring and user-namespace access (unshare -Urn), which is the default on many distributions; no init-namespace root or CAP_NET_ADMIN is needed.\nUI:N - No victim user action is required; the attacker drives the entire exploit autonomously through syscalls and local network namespace setup.\nS:U - Impact is standard host-kernel privilege escalation (root on the same kernel); it does not cross a distinct hypervisor/IOMMU security boundary such as VM-guest-to-host escape.\nC:H - The flaw is a use-after-free on page structures; the known exploit leverages the refcount underflow to obtain stale read access to freed physical pages and extract kernel PTE contents, enabling arbitrary memory disclosure primitives.\nI:H - UAF page refcount corruption enables crafting writable PTE entries against read-only page-cache pages; the public exploit demonstrates integrity compromise by rewriting /etc/passwd and obtaining root via su.\nA:H - Use-after-free of page structures can cause kernel oops/panic during skb teardown; even failed exploitation attempts can crash the system."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/gro.c"],"versions":[{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"1f9c828556416fbe3f49386708ce999fc4d4da06","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"479084ae0e1d9cb7929cb4298d35623de189f80a","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"e334cbf3388fd9334503a778a82d9e9f14dd2f71","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"44bea2032af0425e4ce6d26a8af0ede79db49ec1","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"4db79a322db8c97f7b73b8a347395ef4d685eb40","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/core/gro.c"],"versions":[{"version":"6.0","status":"affected"},{"version":"0","lessThan":"6.0","status":"unaffected","versionType":"semver"},{"version":"6.1.176","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.142","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.92","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.34","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.11","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"6.0","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d"},{"url":"https://git.kernel.org/stable/c/1f9c828556416fbe3f49386708ce999fc4d4da06"},{"url":"https://git.kernel.org/stable/c/479084ae0e1d9cb7929cb4298d35623de189f80a"},{"url":"https://git.kernel.org/stable/c/e334cbf3388fd9334503a778a82d9e9f14dd2f71"},{"url":"https://git.kernel.org/stable/c/44bea2032af0425e4ce6d26a8af0ede79db49ec1"},{"url":"https://git.kernel.org/stable/c/4db79a322db8c97f7b73b8a347395ef4d685eb40"}],"title":"net: 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This vulnerability occurs when `skb_gro_receive()` attempts to merge zerocopy socket buffers (skbs) without properly managing page reference counts, specifically when the `SKBFL_MANAGED_FRAG_REFS` flag is set. An attacker could potentially exploit this to trigger a Use-After-Free (UAF) condition, which is a memory corruption vulnerability that can lead to system instability or potentially arbitrary code execution."}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"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"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-123","description":"Write-what-where Condition","lang":"en","type":"CWE"}]}],"references":[{"tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-46323"},{"name":"RHBZ#2479832","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2479832"},{"tags":["x_sadp-csaf-vex"],"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46323.json"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:47727"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:44230"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:44231"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:44259"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:44262"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:27731"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:44270"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:27735"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:27708"},{"tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:36018"}],"solutions":[{"lang":"en","value":"RHSA-2026:47727: Red Hat OpenShift Container Platform 4.17"},{"lang":"en","value":"RHSA-2026:44230: Red Hat OpenShift Container Platform 4.18"},{"lang":"en","value":"RHSA-2026:44231: Red Hat OpenShift Container Platform 4.19"},{"lang":"en","value":"RHSA-2026:44259: Red Hat OpenShift Container Platform 4.20"},{"lang":"en","value":"RHSA-2026:44262: Red Hat OpenShift Container Platform 4.21"},{"lang":"en","value":"RHSA-2026:27731: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0), Red Hat Enterprise Linux Real Time EUS (v. 10.0), Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)"},{"lang":"en","value":"RHSA-2026:44270: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10)"},{"lang":"en","value":"RHSA-2026:27735: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4), Red Hat Enterprise Linux Real Time E4S (v.9.4), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)"},{"lang":"en","value":"RHSA-2026:27708: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6), Red Hat Enterprise Linux Real Time EUS (v.9.6), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)"},{"lang":"en","value":"RHSA-2026:36018: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9)"}],"timeline":[{"lang":"en","time":"2026-05-19T11:49:44.372Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-05-19T00:00:00.000Z","value":"Made public."}],"title":"kernel: Linux kernel: Use-After-Free in net/gro due to improper handling of zerocopy skbs","workarounds":[{"lang":"en","value":"Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}],"x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"},"providerMetadata":{"orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","shortName":"redhat-SADP","dateUpdated":"2026-08-25T12:05:36.169Z"}}]}}