CVE-2026-98621

{"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"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/net/gue.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "4b9bc21b2396c396d88dd909caaf73d5be6ff593", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}, {"lessThan": "43efb1f997e976f386aa89716f55870cd2cff9ad", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}, {"lessThan": "1eeec0c51fd5598da44080ed96bbd9880021c28b", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}, {"lessThan": "1d664be4ca49d1696e85239236f4988dfc4653c3", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}, {"lessThan": "97f907203321eee2cc9132d5c9eb47698fb41d35", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}, {"lessThan": "40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}, {"lessThan": "c20f755338ca234e523dfc943719f194dfc1f903", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}, {"lessThan": "2566866fc30965d915d0b52b5c3323b362619f0e", "status": "affected", "version": "fe881ef11cf0220f118816181930494d484c4883", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/net/gue.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.0"}, {"lessThan": "4.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.271", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.222", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.189", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.158", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.112", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.55", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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."}], "id": "CVE-2026-98621", "lastModified": "2026-10-19T10:19:26.217", "metrics": {}, "published": "2026-10-18T16:17:14.997", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1d664be4ca49d1696e85239236f4988dfc4653c3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1eeec0c51fd5598da44080ed96bbd9880021c28b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2566866fc30965d915d0b52b5c3323b362619f0e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/43efb1f997e976f386aa89716f55870cd2cff9ad"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4b9bc21b2396c396d88dd909caaf73d5be6ff593"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/97f907203321eee2cc9132d5c9eb47698fb41d35"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c20f755338ca234e523dfc943719f194dfc1f903"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net: gue: reject invalid REMCSUM offsets", "id": "2555040", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2555040"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-787", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet: gue: reject invalid REMCSUM offsets\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.\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.\nReject reversed tuples in validate_gue_flags(), after the existing length\nvalidation, so all GUE parsers enforce the ordering in one place.", "A flaw was found in the Linux kernel's Generic UDP Encapsulation (GUE) networking component. A remote attacker could exploit this vulnerability by sending specially crafted network packets containing invalid remote checksum offsets. This improper input validation causes an integer underflow, allowing an out-of-bounds write when the packet is forwarded to certain network device drivers, which can result in memory corruption or a denial of service (DoS) via a system crash."], "name": "CVE-2026-98621", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-98621\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-98621\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98621.mbox"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,4b9bc21b2396c396d88dd909caaf73d5be6ff593)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,43efb1f997e976f386aa89716f55870cd2cff9ad)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,1eeec0c51fd5598da44080ed96bbd9880021c28b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,1d664be4ca49d1696e85239236f4988dfc4653c3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,97f907203321eee2cc9132d5c9eb47698fb41d35)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,c20f755338ca234e523dfc943719f194dfc1f903)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fe881ef11cf0220f118816181930494d484c4883,2566866fc30965d915d0b52b5c3323b362619f0e)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "4.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,4.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.10.271,5.11.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.15.222,5.16.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.189,6.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.158,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.112,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.55,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.9,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-10-18T18:30:14.375761+00:00", "updated": "2026-10-22T21:45:06.450058+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-190", "CWE-787"]}