{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31448 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-31448 is a critical denial of service vulnerability in Linux kernel, published on 22 Apr 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-2026-31448 and fix it if it is affected.\n\nWhat it is: CVE-2026-31448 is a critical denial of service vulnerability in Linux kernel, published on 22 Apr 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-2026-31448 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-2026-31448/ (Markdown: https://insights.sbomify.com/CVE-2026-31448/index.md)","id":"CVE-2026-31448","markdown":"https://insights.sbomify.com/CVE-2026-31448/index.md","name":"CVE-2026-31448","record":{"aliases":["AZL-83309","BELL-CVE-2026-31448","DEBIAN-CVE-2026-31448","GHSA-m6jj-c3pv-cg65","ROOT-OS-DEBIAN-11-CVE-2026-31448","ROOT-OS-DEBIAN-12-CVE-2026-31448","ROOT-OS-DEBIAN-13-CVE-2026-31448","ROOT-OS-UBUNTU-2204-CVE-2026-31448","ROOT-OS-UBUNTU-2404-CVE-2026-31448","UBUNTU-CVE-2026-31448"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel ext4","requires_auth":"none","summary":"A flaw in the Linux kernel ext4 filesystem allows local attackers to cause a denial of service via infinite loops during directory creation.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":9.4,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-835","name":"Loop with Unreachable Exit Condition"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: avoid infinite loops caused by residual data\n\nOn the mkdir/mknod path, when mapping logical blocks to physical blocks,\nif inserting a new extent into the extent tree fails (in this example,\nbecause the file system disabled the huge file feature when marking the\ninode as dirty), ext4_ext_map_blocks() only calls ext4_free_blocks() to\nreclaim the physical block without deleting the corresponding data in\nthe extent tree. This causes subsequent mkdir operations to reference\nthe previously reclaimed physical block number again, even though this\nphysical block is already being used by the xattr block. Therefore, a\nsituation arises where both the directory and xattr are using the same\nbuffer head block in memory simultaneously.\n\nThe above causes ext4_xattr_block_set() to enter an infinite loop about\n\"inserted\" and cannot release the inode lock, ultimately leading to the\n143s blocking problem mentioned in [1].\n\nIf the metadata is corrupted, then trying to remove some extent space\ncan do even more harm. Also in case EXT4_GET_BLOCKS_DELALLOC_RESERVE\nwas passed, remove space wrongly update quota information.\nJan Kara suggests distinguishing between two cases:\n\n1) The error is ENOSPC or EDQUOT - in this case the filesystem is fully\nconsistent and we must maintain its consistency including all the\naccounting. However these errors can happen only early before we've\ninserted the extent into the extent tree. So current code works correctly\nfor this case.\n\n2) Some other error - this means metadata is corrupted. We should strive to\ndo as few modifications as possible to limit damage. So I'd just skip\nfreeing of allocated blocks.\n\n[1]\nINFO: task syz.0.17:5995 blocked for more than 143 seconds.\nCall Trace:\n inode_lock_nested include/linux/fs.h:1073 [inline]\n __start_dirop fs/namei.c:2923 [inline]\n start_dirop fs/namei.c:2934 [inline]","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":"ext4: avoid infinite loops caused by residual data","id":"CVE-2026-31448","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":6,"next":{"headline":"ext4: validate p_idx bounds in ext4_ext_correct_indexes","id":"CVE-2026-31449"},"packages":[],"prev":{"headline":"ext4: reject mount if bigalloc with s_first_data_block != 0","id":"CVE-2026-31447"},"products":["Linux"],"published":"2026-04-22","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":"partial"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A flaw in the Linux kernel ext4 filesystem allows local attackers to cause a denial of service via infinite loops during directory creation.","url":"https://insights.sbomify.com/CVE-2026-31448/"}