{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-99018 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-99018 is a high-severity vulnerability in Linux, published on 23 Oct 2026."},"fix_prompt":"Check this codebase for CVE-2026-99018 and fix it if it is affected.\n\nWhat it is: CVE-2026-99018 is a high-severity vulnerability in Linux, published on 23 Oct 2026. \nExploitation: There is no known exploitation of CVE-2026-99018 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-2026-99018/ (Markdown: https://insights.sbomify.com/CVE-2026-99018/index.md)","id":"CVE-2026-99018","markdown":"https://insights.sbomify.com/CVE-2026-99018/index.md","name":"CVE-2026-99018","record":{"aliases":["BELL-CVE-2026-99018","DEBIAN-CVE-2026-99018","GHSA-7x79-hrpm-vw9w","UBUNTU-CVE-2026-99018"],"analysis":null,"analysis_generated_by":null,"assigner":"Linux","cpe":[],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: entry: gate shadow call stack reload on sstatus.SPP, not tp\n\nUnder CONFIG_SHADOW_CALL_STACK, handle_exception() reloads the kernel\nshadow call stack pointer (gp) only when the trap came from userspace.\nIt made that decision with scs_load_current_if_task_changed, which\ncompares the trap-time tp (read back from sscratch into s5) against the\ncurrent tp:\n\n\tbeq\t\\prev, tp, _skip_scs\n\tscs_load_current\n_skip_scs:\n\ntp is a user-writable register.  A user task that sets tp to the\nlinear-map address of its own task_struct (\u0026current) before trapping\nmakes the comparison succeed (can achieve by brute force with KASLR\nenable under our test), so the kernel skips scs_load_current and\nkeeps running with the gp that userspace left in place.  Under\nCONFIG_SHADOW_CALL_STACK gp is the shadow call stack pointer and\nload_global_pointer is a no-op, so the compiler-emitted\n\"sd ra, -8(gp)\" / \"ld ra, -8(gp)\" in every non-leaf function then write\nto, and return through, an attacker-controlled address -- an\nunprivileged kernel arbitrary-write and control-flow-hijack primitive.\nThe poisoned gp is saved to task_struct.scs_sp on return, so the reload\nis skipped on every subsequent entry as well.\n\nDecide \"came from userspace\" from the hardware sstatus.SPP bit (already\nin s1 at this point) instead of from tp, mirroring the check that\nret_from_exception already uses a few instructions later.  SPP is\nwritten by hardware on trap entry and cannot be forged from U-mode.\nLegitimate behaviour is unchanged: user entries (SPP=0) reload the task\nshadow call stack, nested kernel entries (SPP=1) skip it.","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":"riscv: entry: gate shadow call stack reload on sstatus.SPP, not tp","id":"CVE-2026-99018","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":null,"year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"scsi: ch: Do not keep references to data transfer element devices","id":"CVE-2026-99019"},"packages":[],"prev":{"headline":"riscv: errata: select RISCV_ALTERNATIVE_EARLY for THEAD GHOSTWRITE","id":"CVE-2026-99017"},"products":["Linux"],"published":"2026-10-23","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-24","vendors":["Linux"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2026-99018/"}