{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98621","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.360Z","datePublished":"2026-10-18T15:19:41.211Z","dateUpdated":"2026-10-19T09:22:49.371Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-19T09:22:49.371Z"},"descriptions":[{"lang":"en","value":"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/gue.h"],"versions":[{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"4b9bc21b2396c396d88dd909caaf73d5be6ff593","status":"affected","versionType":"git"},{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"43efb1f997e976f386aa89716f55870cd2cff9ad","status":"affected","versionType":"git"},{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"1eeec0c51fd5598da44080ed96bbd9880021c28b","status":"affected","versionType":"git"},{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"1d664be4ca49d1696e85239236f4988dfc4653c3","status":"affected","versionType":"git"},{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"97f907203321eee2cc9132d5c9eb47698fb41d35","status":"affected","versionType":"git"},{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f","status":"affected","versionType":"git"},{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"c20f755338ca234e523dfc943719f194dfc1f903","status":"affected","versionType":"git"},{"version":"fe881ef11cf0220f118816181930494d484c4883","lessThan":"2566866fc30965d915d0b52b5c3323b362619f0e","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/gue.h"],"versions":[{"version":"4.0","status":"affected"},{"version":"0","lessThan":"4.0","status":"unaffected","versionType":"semver"},{"version":"5.10.271","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.222","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.189","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.158","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.112","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.55","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.9","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","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":"4.0","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"7.3"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/4b9bc21b2396c396d88dd909caaf73d5be6ff593"},{"url":"https://git.kernel.org/stable/c/43efb1f997e976f386aa89716f55870cd2cff9ad"},{"url":"https://git.kernel.org/stable/c/1eeec0c51fd5598da44080ed96bbd9880021c28b"},{"url":"https://git.kernel.org/stable/c/1d664be4ca49d1696e85239236f4988dfc4653c3"},{"url":"https://git.kernel.org/stable/c/97f907203321eee2cc9132d5c9eb47698fb41d35"},{"url":"https://git.kernel.org/stable/c/40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f"},{"url":"https://git.kernel.org/stable/c/c20f755338ca234e523dfc943719f194dfc1f903"},{"url":"https://git.kernel.org/stable/c/2566866fc30965d915d0b52b5c3323b362619f0e"}],"title":"net: gue: reject invalid REMCSUM offsets","x_generator":{"engine":"bippy-1.2.0"}}}}