{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46273","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-13T15:03:33.109Z","datePublished":"2026-06-03T16:19:18.056Z","dateUpdated":"2026-08-07T12:54:55.431Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:30:56.753Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nibmveth: Disable GSO for packets with small MSS\n\nSome physical adapters on Power systems do not support segmentation\noffload when the MSS is less than 224 bytes. Attempting to send such\npackets causes the adapter to freeze, stopping all traffic until\nmanually reset.\n\nImplement ndo_features_check to disable GSO for packets with small MSS\nvalues. The network stack will perform software segmentation instead.\n\nThe 224-byte minimum matches ibmvnic\ncommit <f10b09ef687f> (\"ibmvnic: Enforce stronger sanity checks\non GSO packets\")\nwhich uses the same physical adapters in SEA configurations.\n\nThe issue occurs specifically when the hardware attempts to perform\nsegmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets\n(gso_segs == 1) do not trigger the problematic LSO code path and are\ntransmitted normally without segmentation.\n\nAdd an ndo_features_check callback to disable GSO when MSS < 224 bytes.\nAlso call vlan_features_check() to ensure proper handling of VLAN packets,\nparticularly QinQ (802.1ad) configurations where the hardware parser may\nnot support certain offload features.\n\nValidated using iptables to force small MSS values. Without the fix,\nthe adapter freezes. With the fix, packets are segmented in software\nand transmission succeeds. Comprehensive regression testing completedd\n(MSS tests, performance, stability)."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","baseScore":8.6,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - A remote attacker on a network path to an IBM Power LPAR can trigger the bug by advertising TCP MSS below 224 bytes and causing large outbound traffic that is GSO-transmitted on ibmveth.\nAC:L - The attacker controls TCP MSS in the handshake and can reliably generate multi-segment GSO transmits (gso_segs > 1); no race or rare victim state is required beyond normal TCP and TSO-enabled ibmveth deployments.\nPR:N - Exploitation requires only the ability to send TCP traffic to a listening service on the victim; no local account, capabilities, or namespace privileges on the target are needed.\nUI:N - No victim user action is required beyond the system running network-exposed services that accept TCP connections.\nS:C - On shared SEA/backing-adapter Power deployments, freezing the physical adapter can stop network traffic for other LPARs or tenants beyond the attacking partition’s security boundary.\nC:N - The failure mode is adapter freeze/DoS with no kernel memory corruption, out-of-bounds access, or information disclosure primitive described or implied in the fix.\nI:N - There is no arbitrary memory write or code execution path; impact is loss of network function rather than modification of kernel or application data integrity.\nA:H - The adapter freezes and all traffic stops until manual reset, constituting complete, persistent loss of network availability for affected systems."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/ibm/ibmveth.c","drivers/net/ethernet/ibm/ibmveth.h"],"versions":[{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"86fc64584811d43c9ccd74447de58620189d8b77","status":"affected","versionType":"git"},{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"9a5e984d7af910e46dcbed3ce77873e000a4f77d","status":"affected","versionType":"git"},{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"1cdf5dbcec988d06f5f720bdf89e91073f77fa10","status":"affected","versionType":"git"},{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"82bc89fbb82d9396fb4eaee8720ea85e2e787957","status":"affected","versionType":"git"},{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"db8012c631cb845e9ae2b4b531e17d86c9519755","status":"affected","versionType":"git"},{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"c1f261863e65b508f37416dfbc5c5d911c9b9233","status":"affected","versionType":"git"},{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"3af24f0c4c31f18a4a2d927990759194832bb6e9","status":"affected","versionType":"git"},{"version":"8641dd85799f85bef5f0d1f87356aaa12cb2195e","lessThan":"cc427d24ac6442ffdeafd157a63c7c5b73ed4de4","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/ibm/ibmveth.c","drivers/net/ethernet/ibm/ibmveth.h"],"versions":[{"version":"4.2","status":"affected"},{"version":"0","lessThan":"4.2","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.140","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.88","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.30","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.7","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":"4.2","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.6.140"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.12.88"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.18.30"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"7.0.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/86fc64584811d43c9ccd74447de58620189d8b77"},{"url":"https://git.kernel.org/stable/c/9a5e984d7af910e46dcbed3ce77873e000a4f77d"},{"url":"https://git.kernel.org/stable/c/1cdf5dbcec988d06f5f720bdf89e91073f77fa10"},{"url":"https://git.kernel.org/stable/c/82bc89fbb82d9396fb4eaee8720ea85e2e787957"},{"url":"https://git.kernel.org/stable/c/db8012c631cb845e9ae2b4b531e17d86c9519755"},{"url":"https://git.kernel.org/stable/c/c1f261863e65b508f37416dfbc5c5d911c9b9233"},{"url":"https://git.kernel.org/stable/c/3af24f0c4c31f18a4a2d927990759194832bb6e9"},{"url":"https://git.kernel.org/stable/c/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4"}],"title":"ibmveth: Disable GSO for packets with small MSS","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-400","lang":"en","description":"CWE-400 Uncontrolled Resource Consumption"}]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-12T17:33:39.400783Z","id":"CVE-2026-46273","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-07T12:54:55.431Z"}}]}}