{"id":"CVE-2026-98621","revision":"ab10e1f319ab4867864dbbb90dc4331a","records":[{"revision":"ab10e1f319ab4867864dbbb90dc4331a","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98621","aliases":[],"title":"net: gue: reject invalid REMCSUM offsets","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gue: reject invalid REMCSUM offsets\n\nThe REMCSUM option carries an absolute checksum start and checksum field\noffset. gue_remcsum() passes them to skb_remcsum_process(), whose\npartial path stores offset - start in the u16 skb->csum_offset variable.\nIf offset is less than start, this underflows.\n\nA forwarded packet can retain CHECKSUM_PARTIAL and reach a NETIF_F_HW_CSUM\ndriver which trusts the metadata, leading skb_copy_and_csum_dev() to write\ntwo bytes about 64 KiB beyond the destination buffer.\n\nReject reversed tuples in validate_gue_flags(), after the existing length\nvalidation, so all GUE parsers enforce the ordering in one place.","state":0,"publishedAt":"2026-10-18T15:19:41.211+00:00","modifiedAt":"2026-10-19T09:22:49.371+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/net/gue.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"4b9bc21b2396c396d88dd909caaf73d5be6ff593\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"43efb1f997e976f386aa89716f55870cd2cff9ad\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"1eeec0c51fd5598da44080ed96bbd9880021c28b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"1d664be4ca49d1696e85239236f4988dfc4653c3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"97f907203321eee2cc9132d5c9eb47698fb41d35\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"c20f755338ca234e523dfc943719f194dfc1f903\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe881ef11cf0220f118816181930494d484c4883\",\n                            \"lessThan\": \"2566866fc30965d915d0b52b5c3323b362619f0e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/net/gue.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.271\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.222\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.112\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.55\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.9\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/4b9bc21b2396c396d88dd909caaf73d5be6ff593","https://git.kernel.org/stable/c/43efb1f997e976f386aa89716f55870cd2cff9ad","https://git.kernel.org/stable/c/1eeec0c51fd5598da44080ed96bbd9880021c28b","https://git.kernel.org/stable/c/1d664be4ca49d1696e85239236f4988dfc4653c3","https://git.kernel.org/stable/c/97f907203321eee2cc9132d5c9eb47698fb41d35","https://git.kernel.org/stable/c/40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f","https://git.kernel.org/stable/c/c20f755338ca234e523dfc943719f194dfc1f903","https://git.kernel.org/stable/c/2566866fc30965d915d0b52b5c3323b362619f0e"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98621","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98621","identifiers":["CVE-2026-98621"]},"retained":false,"historicalAffected":[]}],"coverage":[]}