{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-63984 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-63984 is a critical vulnerability in Linux, published on 19 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-63984 and fix it if it is affected.\n\nWhat it is: CVE-2026-63984 is a critical vulnerability in Linux, published on 19 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-63984 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-63984/ (Markdown: https://insights.sbomify.com/CVE-2026-63984/index.md)","id":"CVE-2026-63984","markdown":"https://insights.sbomify.com/CVE-2026-63984/index.md","name":"CVE-2026-63984","record":{"aliases":["BELL-CVE-2026-63984","DEBIAN-CVE-2026-63984","GHSA-6hh9-w4p2-c5qm","ROOT-OS-UBUNTU-2204-CVE-2026-63984","UBUNTU-CVE-2026-63984"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["data_modify","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"An integer overflow in the Linux kernel IPv6 RPL implementation allows memory corruption and potential denial of service via crafted packets.","user_interaction":"not_required","vuln_class":"integer_overflow"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":9.8,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-190","name":"Integer Overflow or Wraparound"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()\n\nipv6_rpl_srh_decompress() computes:\n\n    outhdr-\u003ehdrlen = (((n + 1) * sizeof(struct in6_addr)) \u003e\u003e 3);\n\nhdrlen is __u8. For n \u003e= 127 the result exceeds 255 and silently\ntruncates. With n=127 (cmpri=15, cmpre=15, pad=0, hdrlen=16):\n\n    (128 * 16) \u003e\u003e 3 = 256, truncated to 0 as __u8\n\nThe caller in ipv6_rpl_srh_rcv() then places the compressed header\nat buf + ((ohdr-\u003ehdrlen + 1) \u003c\u003c 3). With hdrlen=0 this is buf + 8,\nbut the decompressed region occupies buf[0..2055] (8-byte header\nplus 128 full addresses). The compressed header overlaps the\ndecompressed data, and ipv6_rpl_srh_compress() writes into this\noverlap, corrupting the routing header of the forwarded packet.\n\nThe existing guard at exthdrs.c:546 checks (n + 1) \u003e 255, which\nprevents n+1 from overflowing unsigned char (the segments_left\nfield), but does not prevent the computed hdrlen from overflowing\n__u8. n=127 passes because 128 \u003c= 255, yet hdrlen=256 does not\nfit.\n\nTighten the bound to (n + 1) \u003e 127. This caps n at 126, giving\nhdrlen = (127 * 16) \u003e\u003e 3 = 254, which fits in __u8. The compressed\nheader then lands at buf + ((254 + 1) \u003c\u003c 3) = buf + 2040, exactly\npast the decompressed region (buf[0..2039]). No overlap. 127\nsegments is well beyond any realistic RPL deployment.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()","id":"CVE-2026-63984","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"integer_overflow","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"ethtool: eeprom: add more safeties to EEPROM Netlink fallback","id":"CVE-2026-63985"},"packages":[],"prev":{"headline":"net/sched: fix packet loop on netem when duplicate is on","id":"CVE-2026-63983"},"products":["Linux"],"published":"2026-07-19","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"An integer overflow in the Linux kernel IPv6 RPL implementation allows memory corruption and potential denial of service via crafted packets.","url":"https://insights.sbomify.com/CVE-2026-63984/"}