{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46321", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.112Z", "datePublished": "2026-06-09T12:11:13.872Z", "dateUpdated": "2026-08-05T12:31:16.239Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:31:16.239Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntun: free page on short-frame rejection in tun_xdp_one()\n\ntun_xdp_one() returns -EINVAL on a frame shorter than ETH_HLEN without\nfreeing the page that vhost_net_build_xdp() allocated for it.\ntun_sendmsg() discards that -EINVAL and still returns total_len, so\nvhost_tx_batch() takes the success path and never frees the page; each\nshort frame in a batch leaks one page-frag chunk.\n\nA local process that can open /dev/net/tun and /dev/vhost-net can hit\nthis path: it attaches a tun/tap device as the vhost-net backend and\nfeeds TX descriptors whose length minus the virtio-net header is below\nETH_HLEN. Each kick leaks the page-frag chunks for that batch, and a\ntight submission loop exhausts host memory and triggers an OOM panic.\nFree the page before returning -EINVAL, matching the XDP-program error\npath in the same function." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is reached via local host interfaces (/dev/net/tun and /dev/vhost-net ioctls/sendmsg) or from a KVM guest through virtio-net TX descriptors processed by vhost-net, not via remote network packets to the host stack.\nAC:L - An attacker reliably triggers the leak by repeatedly submitting TX frames whose length minus the virtio-net header is below ETH_HLEN; no races or attacker-uncontrollable layout conditions are required.\nPR:N - A malicious KVM guest on a host using vhost-net with a tun/tap backend needs no host privileges—only the ability to craft short virtio-net TX descriptors—while a direct host attacker can also obtain CAP_NET_ADMIN via unprivileged user namespaces.\nUI:N - Exploitation requires no victim interaction beyond normal VM or namespace operation; the attacker drives the vhost TX path directly in a tight loop.\nS:C - In the highest-impact cloud/KVM deployment, an unprivileged guest VM crosses the hypervisor security boundary to exhaust host kernel memory and panic the host, affecting resources outside the guest's security scope.\nC:N - The bug is a page-fragment memory leak with no out-of-bounds access, use-after-free, or information disclosure; freed pages are simply never returned to the allocator.\nI:N - No kernel memory corruption or data modification occurs; the only effect is unbounded consumption of page-frags leading to denial of service.\nA:H - Sustained submission of short batched frames leaks one page-frag per frame, exhausts host memory, and can trigger an OOM kernel panic as described in the fix commit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/tun.c" ], "versions": [ { "version": "6100e0237204890269e3f934acfc50d35fd6f319", "lessThan": "0a6f46a9332ad6958992d64d3b3a81a80b2ca940", "status": "affected", "versionType": "git" }, { "version": "589382f50b4a5d90d16d8bc9dcbc0e927a3e39b2", "lessThan": "0e8211fcf9426f5adddf32516ba0f400ceb9544d", "status": "affected", "versionType": "git" }, { "version": "ad6b3f622ccfb4bfedfa53b6ebd91c3d1d04f146", "lessThan": "e915445942af6dcea628bf66d6241641201a0c41", "status": "affected", "versionType": "git" }, { "version": "d5ad89b7d01ed4e66fd04734fc63d6e78536692a", "lessThan": "5b34f9e4fe2f203724a6e893d6df0316b9670057", "status": "affected", "versionType": "git" }, { "version": "049584807f1d797fc3078b68035450a9769eb5c3", "lessThan": "69863ff2720a0e9871f1a5710f2a33a94217fee0", "status": "affected", "versionType": "git" }, { "version": "049584807f1d797fc3078b68035450a9769eb5c3", "lessThan": "37a1c268c2c8090bf4dc552d732bd23ba36f8eb0", "status": "affected", "versionType": "git" }, { "version": "049584807f1d797fc3078b68035450a9769eb5c3", "lessThan": "98c67be9eb9de72465a071949e84a3cdb8fab5a3", "status": "affected", "versionType": "git" }, { "version": "049584807f1d797fc3078b68035450a9769eb5c3", "lessThan": "f4feb1e20058e407cb00f45aff47f5b7e19a6bbf", "status": "affected", "versionType": "git" }, { "version": "32b0aaba5dbc85816898167d9b5d45a22eae82e9", "status": "affected", "versionType": "git" }, { "version": "a9d1c27e2ee3b0ea5d40c105d6e728fc114470bb", "status": "affected", "versionType": "git" }, { "version": "8418f55302fa1d2eeb73e16e345167e545c598a5", "status": "affected", "versionType": "git" }, { "version": "5.10.223", "lessThan": "5.10.259", "status": "affected", "versionType": "semver" }, { "version": "5.15.164", "lessThan": "5.15.210", "status": "affected", "versionType": "semver" }, { "version": "6.1.102", "lessThan": "6.1.176", "status": "affected", "versionType": "semver" }, { "version": "6.6.43", "lessThan": "6.6.143", "status": "affected", "versionType": "semver" }, { "version": "5.4.281", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "6.9.12", "lessThan": "6.10", "status": "affected", "versionType": "semver" }, { "version": "6.10.2", "lessThan": "6.11", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/tun.c" ], "versions": [ { "version": "6.11", "status": "affected" }, { "version": "0", "lessThan": "6.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.259", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.12", "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": "5.10.223", "versionEndExcluding": "5.10.259" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.164", "versionEndExcluding": "5.15.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.102", "versionEndExcluding": "6.1.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.43", "versionEndExcluding": "6.6.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.12.93" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.18.35" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.0.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.281" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0a6f46a9332ad6958992d64d3b3a81a80b2ca940" }, { "url": "https://git.kernel.org/stable/c/0e8211fcf9426f5adddf32516ba0f400ceb9544d" }, { "url": "https://git.kernel.org/stable/c/e915445942af6dcea628bf66d6241641201a0c41" }, { "url": "https://git.kernel.org/stable/c/5b34f9e4fe2f203724a6e893d6df0316b9670057" }, { "url": "https://git.kernel.org/stable/c/69863ff2720a0e9871f1a5710f2a33a94217fee0" }, { "url": "https://git.kernel.org/stable/c/37a1c268c2c8090bf4dc552d732bd23ba36f8eb0" }, { "url": "https://git.kernel.org/stable/c/98c67be9eb9de72465a071949e84a3cdb8fab5a3" }, { "url": "https://git.kernel.org/stable/c/f4feb1e20058e407cb00f45aff47f5b7e19a6bbf" } ], "title": "tun: free page on short-frame rejection in tun_xdp_one()", "x_generator": { "engine": "bippy-1.2.0" } } } }