CVE-2026-31713

#include <fuse_lowlevel.h> #include <stdlib.h> #include <stdio.h> // Callback for FUSE_INIT static void fl_init(void *userdata, struct fuse_conn_info *conn, struct fuse_bufvec *bufv) { printf("Server received INIT, simulating crash...\n"); // Exit immediately during init to trigger the hang on kernel side exit(1); } int main(int argc, char *argv[]) { struct fuse_args args = FUSE_ARGS_INIT(argc, argv); struct fuse_session *se; struct fuse_cmdline_opts opts; if (fuse_parse_cmdline(&args, &opts) != 0) return 1; se = fuse_lowlevel_new(&args, &(struct fuse_lowlevel_ops){ .init = fl_init }, sizeof(struct fuse_lowlevel_ops), NULL); if (!se) { fuse_unmount(opts.mountpoint, NULL); return 1; } // Mount the filesystem (Sync mode) if (fuse_mount(se, opts.mountpoint) != 0) { return 1; } // Enter the loop, but will exit immediately in init callback fuse_session_loop(se); return 0; }

{"cve": {"id": "CVE-2026-31713", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T14:16:21.390", "lastModified": "2026-05-06T21:13:45.243", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: abort on fatal signal during sync init\n\nWhen sync init is used and the server exits for some reason (error, crash)\nwhile processing FUSE_INIT, the filesystem creation will hang. The reason\nis that while all other threads will exit, the mounting thread (or process)\nwill keep the device fd open, which will prevent an abort from happening.\n\nThis is a regression from the async mount case, where the mount was done\nfirst, and the FUSE_INIT processing afterwards, in which case there's no\nsuch recursive syscall keeping the fd open."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "6.18.25", "matchCriteriaId": "5C53A705-D2E9-401E-9B1B-DBC8C4FE5181"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.0.2", "matchCriteriaId": "1BD58F1E-7C20-4C0D-92A2-FAC5CBFBE8A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0c7fca880a40a209a9c92be14143996d14b93ff6", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/204aa22a686bfee48daca7db620c1e017615f2ff", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/300e812b882a174dca675d8028684001ad5826bc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}