{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-39726 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-39726 is a critical vulnerability in Linux kernel, published on 5 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-39726 and fix it if it is affected.\n\nWhat it is: CVE-2025-39726 is a critical vulnerability in Linux kernel, published on 5 Sep 2025. 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-2025-39726 in the wild and no public exploit code.\n\nAffected product: Linux kernel. 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-2025-39726/ (Markdown: https://insights.sbomify.com/CVE-2025-39726/index.md)","id":"CVE-2025-39726","markdown":"https://insights.sbomify.com/CVE-2025-39726/index.md","name":"CVE-2025-39726","record":{"aliases":["AZL-66932","BELL-CVE-2025-39726","DEBIAN-CVE-2025-39726","GHSA-6vq8-h5mr-8xhr","ROOT-OS-DEBIAN-11-CVE-2025-39726","ROOT-OS-DEBIAN-12-CVE-2025-39726","ROOT-OS-UBUNTU-2204-CVE-2025-39726","ROOT-OS-UBUNTU-2404-CVE-2025-39726","UBUNTU-CVE-2025-39726"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel driver","requires_auth":"none","summary":"A race condition in the s390 ISM driver allows concurrent commands to corrupt device state, causing PCI errors and connection failures.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"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-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ism: fix concurrency management in ism_cmd()\n\nThe s390x ISM device data sheet clearly states that only one\nrequest-response sequence is allowable per ISM function at any point in\ntime.  Unfortunately as of today the s390/ism driver in Linux does not\nhonor that requirement. This patch aims to rectify that.\n\nThis problem was discovered based on Aliaksei's bug report which states\nthat for certain workloads the ISM functions end up entering error state\n(with PEC 2 as seen from the logs) after a while and as a consequence\nconnections handled by the respective function break, and for future\nconnection requests the ISM device is not considered -- given it is in a\ndysfunctional state. During further debugging PEC 3A was observed as\nwell.\n\nA kernel message like\n[ 1211.244319] zpci: 061a:00:00.0: Event 0x2 reports an error for PCI function 0x61a\nis a reliable indicator of the stated function entering error state\nwith PEC 2. Let me also point out that a kernel message like\n[ 1211.244325] zpci: 061a:00:00.0: The ism driver bound to the device does not support error recovery\nis a reliable indicator that the ISM function won't be auto-recovered\nbecause the ISM driver currently lacks support for it.\n\nOn a technical level, without this synchronization, commands (inputs to\nthe FW) may be partially or fully overwritten (corrupted) by another CPU\ntrying to issue commands on the same function. There is hard evidence that\nthis can lead to DMB token values being used as DMB IOVAs, leading to\nPEC 2 PCI events indicating invalid DMA. But this is only one of the\nfailure modes imaginable. In theory even completely losing one command\nand executing another one twice and then trying to interpret the outputs\nas if the command we intended to execute was actually executed and not\nthe other one is also possible.  Frankly, I don't feel confident about\nproviding an exhaustive list of possible consequences.","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":"s390/ism: fix concurrency management in ism_cmd()","id":"CVE-2025-39726","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2025"},"n_packages":0,"n_references":4,"next":{"headline":"mm: swap: fix potential buffer overflow in setup_clusters()","id":"CVE-2025-39727"},"packages":[],"prev":{"headline":"mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list","id":"CVE-2025-39725"},"products":["Linux"],"published":"2025-09-05","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"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":"2026-10-15","vendors":["Linux"]},"summary":"A race condition in the s390 ISM driver allows concurrent commands to corrupt device state, causing PCI errors and connection failures.","url":"https://insights.sbomify.com/CVE-2025-39726/"}