{ "cveId": "CVE-2026-98598", "url": "https://patchblox.com/security/cve/CVE-2026-98598", "summary": "CVE-2026-98598 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-98598, released October 19, 2026. It is not reported as exploited. Patch Radar priority: Routine.", "title": "ipv6: Prevent rt6_insert_exception() for dying fib6_info.", "description": "In the Linux kernel, the following vulnerability has been resolved: ipv6: Prevent rt6_insert_exception() for dying fib6_info. Before the cited commit, fib6_nh_flush_exceptions() always set from-\u003Eexception_bucket_flushed = 1 under rt6_exception_lock to prevent rt6_insert_exception() from inserting a new exception for a dying fib6_info. The flag was replaced with the FIB6_EXCEPTION_BUCKET_FLUSHED bit stored in nh-\u003Ert6i_exception_bucket. The problem is that now the bit is only set when the bucket is not NULL and fib6_nh_flush_exceptions() is called from fib6_nh_release() after fib6_ref has already reached zero. If rt6_insert_exception() is called while the target fib6_info is being removed via fib6_purge_rt(), a new exception could be created successfully because rt6_flush_exceptions() no longer sets the bit. This creates a reference cycle between the fib6_info and the exception route, leaking the fib6_info, its nexthop device, and all per-CPU routes in fib6_nh-\u003Ert6i_pcpu, which stalls netdev unregistration. [ 34.680602] unregister_netdevice: waiting for gre6 to become free. Usage count = 68 [ 44.920675] unregister_netdevice: waiting for gre6 to become free. Usage count = 68 [ 55.176582] unregister_netdevice: waiting for gre6 to become free. Usage count = 68 Let\u0027s call fib6_drop_pcpu_from() before rt6_flush_exceptions(), to set fib6_destroying before rt6_exception_lock, and check f6i-\u003Efib6_destroying in rt6_insert_exception(). Note that FIB6_EXCEPTION_BUCKET_FLUSHED logic is dead and we can clean it up in net-next.", "published": "2026-10-18T16:17:12Z", "severity": "Moderate", "cvss": 4.1, "epss": 0.00198, "epssPercentile": 0.09597, "priority": "Routine", "priorityTier": 4, "exploited": false, "vendorExploited": false, "disclosed": false, "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98598", "fixes": [ { "platform": "linux", "product": "bpftool6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "bpftool6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel-livepatch-6.18.56-125.164", "release": "amzn 2023", "fixedVersion": "1:1.0-0.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-aarch64", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-x86_64", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-headers", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra-common", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-tools", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-tools-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-tools-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "linux", "release": "Debian 14", "fixedVersion": "7.2.9-1", "fix": "DEBIAN-CVE-2026-98598", "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-98598", "released": "2026-10-19T16:27:52Z" }, { "platform": "linux", "product": "microvm-kernel6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "python3-perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "python3-perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" } ], "noFixYet": [], "dataAsOf": "2026-11-08T13:06:02Z", "attribution": { "text": "Data: Patchblox Patch Radar", "url": "https://patchblox.com/security/patch-radar", "terms": "https://patchblox.com/security/patch-radar/use-the-data" } }