{"id":"CVE-2026-63984","title":"kernel: ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress() (CVE-2026-63984)","summary":"A flaw was found in the Linux kernel's IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) segment routing header (SRH) decompression function, ipv6_rpl_srh_decompress(). An integer overflow occurs when processing a specially craf…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","cwe":"CWE-190","vendor":"Red Hat","product":"Red Hat Enterprise Linux BaseOS E4S (v.9.4)","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 9","enterprise_linux_appstream_eus_v_10_0","enterprise_linux_appstream_e4s_v_9_4","enterprise_linux_appstream_eus_v_9_6","enterprise_linux_appstream_v_9","enterprise_linux_baseos_eus_v_10_0","enterprise_linux_baseos_e4s_v_9_4","enterprise_linux_baseos_eus_v_9_6","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_eus_v_10_0","codeready_linux_builder_eus_v_9_6","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_eus_v_10_0","enterprise_linux_real_time_for_nfv_e4s_v_9_4","enterprise_linux_real_time_for_nfv_eus_v_9_6","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_eus_v_10_0","enterprise_linux_real_time_e4s_v_9_4","enterprise_linux_real_time_eus_v_9_6","enterprise_linux_real_time_v_9"],"patched":["enterprise_linux_appstream_eus_v_10_0","enterprise_linux_appstream_e4s_v_9_4","enterprise_linux_appstream_eus_v_9_6","enterprise_linux_appstream_v_9","enterprise_linux_baseos_eus_v_10_0","enterprise_linux_baseos_e4s_v_9_4","enterprise_linux_baseos_eus_v_9_6","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_eus_v_10_0","codeready_linux_builder_eus_v_9_6","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_real_time_for_nfv_eus_v_10_0","enterprise_linux_real_time_for_nfv_e4s_v_9_4","enterprise_linux_real_time_for_nfv_eus_v_9_6","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_eus_v_10_0","enterprise_linux_real_time_e4s_v_9_4","enterprise_linux_real_time_eus_v_9_6","enterprise_linux_real_time_v_9"],"published":"2026-07-19","updated":"2026-10-16","sourceUpdated":"2026-10-16T17:34:29+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63984.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63984.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63984"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2502395"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63984"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63984"},{"url":"https://lore.kernel.org/linux-cve-announce/2026071902-CVE-2026-63984-8dc3@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:83707"},{"url":"https://access.redhat.com/errata/RHSA-2026:77218"},{"url":"https://access.redhat.com/errata/RHSA-2026:77219"},{"url":"https://access.redhat.com/errata/RHSA-2026:76739"},{"url":"https://git.kernel.org/stable/c/75b3680047bf09af8e7e471a7a6ddf2ce5847f56"},{"url":"https://git.kernel.org/stable/c/fd238c51b0fa5390cceca9f1ac5a9ffda8063eed"},{"url":"https://git.kernel.org/stable/c/3618b34942b76471d044369bfd30d58c39068bf1"},{"url":"https://git.kernel.org/stable/c/97e06791368c01f0ad2a4b3269c2abe19485ca32"},{"url":"https://git.kernel.org/stable/c/de02fc049352af5a9595f015511222d0a85c326b"},{"url":"https://git.kernel.org/stable/c/6fe1cb312038516cb4d9fa089d700af7059f1a64"},{"url":"https://git.kernel.org/stable/c/c0487a9c1e116cf349e2d1f302d9019670460858"},{"url":"https://git.kernel.org/stable/c/9d5e7a46a9f6d8f503b41bfefef70659845f1679"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00514,"epssPercentile":0.42522,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:34:39.184194Z"},"scores":{"vendor":7,"cna":9.8},"ingestedAt":"2026-10-16T17:24:46.787Z","slug":"CVE-2026-63984","body":"## Overview\n\nA flaw was found in the Linux kernel's IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) segment routing header (SRH) decompression function, ipv6_rpl_srh_decompress(). An integer overflow occurs when processing a specially crafted IPv6 packet, causing the header length calculation to truncate. This truncation leads to an overlap between the compressed header and decompressed data, which can result in the corruption of the routing header in forwarded packets. This vulnerability could allow a remote attacker to cause data corruption.\n\n## Vendor advisories\n\n- **RHSA-2026:83707** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0), Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0), Red Hat Enterprise Linux Real Time EUS (v. 10.0) · released 2026-10-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:83707)\n- **RHSA-2026:77218** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4), Red Hat Enterprise Linux Real Time E4S (v.9.4) · released 2026-10-07 · [advisory](https://access.redhat.com/errata/RHSA-2026:77218)\n- **RHSA-2026:77219** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6), Red Hat Enterprise Linux Real Time EUS (v.9.6) · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:77219)\n- **RHSA-2026:76739** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76739)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63984.json)\n\n**kernel: ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()** — rated Moderate by Red Hat. Released 2026-07-19, updated 2026-10-16.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 9\n\nFixed:\n\n- Red Hat Enterprise Linux AppStream EUS (v. 10.0)\n- Red Hat Enterprise Linux AppStream E4S (v.9.4)\n- Red Hat Enterprise Linux AppStream EUS (v.9.6)\n- Red Hat Enterprise Linux AppStream (v. 9)\n- Red Hat Enterprise Linux BaseOS EUS (v. 10.0)\n- Red Hat Enterprise Linux BaseOS E4S (v.9.4)\n- Red Hat Enterprise Linux BaseOS EUS (v.9.6)\n- Red Hat Enterprise Linux BaseOS (v. 9)\n- Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)\n- Red Hat CodeReady Linux Builder EUS (v.9.6)\n- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)\n- Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)\n- Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)\n- Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)\n- Red Hat Enterprise Linux Real Time for NFV (v. 9)\n- Red Hat Enterprise Linux Real Time EUS (v. 10.0)\n- Red Hat Enterprise Linux Real Time E4S (v.9.4)\n- Red Hat Enterprise Linux Real Time EUS (v.9.6)\n- Red Hat Enterprise Linux Real Time (v. 9)\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n\nNot affected:\n\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n\n## Remediation\n\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\n\nhttps://access.redhat.com/articles/11258\n\nThe system must be rebooted for this update to take effect.\n\nRed Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.\n\nBecause of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:83707\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\n\nhttps://access.redhat.com/articles/11258\n\nThe system must be rebooted for this update to take effect.\n\nRed Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.\n\nBecause of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:77218\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\n\nhttps://access.redhat.com/articles/11258\n\nThe system must be rebooted for this update to take effect.\n\nRed Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.\n\nBecause of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:77219","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":223804,"id":"CVE-2026-63984","ts":1792238435189,"field":"cvss","old":"9.8","new":"7"},{"seq":223803,"id":"CVE-2026-63984","ts":1792238435189,"field":"severity","old":"critical","new":"high"}]}