CVE-2026-31693

/* * Conceptual PoC for CVE-2026-31693 * This PoC demonstrates the logic to trigger CIFS replay mechanism. * Note: Actual exploitation requires specific kernel versions and environments. */ #include <stdio.h> #include <stdlib.h> #include <sys/mount.h> #include <unistd.h> int main() { printf("[+] Attempting to trigger CIFS replay logic...\n"); // 1. Setup: Attacker needs a way to interact with CIFS. // This usually involves mounting a share or accessing a mounted point. // In a real exploit, the attacker would control the network or the server. // 2. Trigger: Perform operations that induce a request replay. // This could involve network interruption or specific I/O patterns. // The goal is to hit the 'replay' label in the kernel code. // Example (Pseudo-code for interaction): // mount("//server/share", "/mnt/cifs", "cifs", 0, "user=guest"); // fd = open("/mnt/cifs/file", O_RDWR); // write(fd, data, size); // Trigger potential replay scenario printf("[!] If vulnerable, the kernel fails to initialize local variables on replay.\n"); printf("[!] This may lead to kernel panic or privilege escalation.\n"); return 0; }

{"cve": {"id": "CVE-2026-31693", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-30T12:16:24.103", "lastModified": "2026-05-07T12:49:05.780", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: some missing initializations on replay\n\nIn several places in the code, we have a label to signify\nthe start of the code where a request can be replayed if\nnecessary. However, some of these places were missing the\nnecessary reinitializations of certain local variables\nbefore replay.\n\nThis change makes sure that these variables get initialized\nafter the label."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-908"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.32", "versionEndExcluding": "6.6.128", "matchCriteriaId": "1ACC9D83-6159-4283-ABFF-6CB26A4C186A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8.1", "versionEndExcluding": "6.12.75", "matchCriteriaId": "2A2F9210-271A-411D-8364-CAF6CDDEC6C0"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.8:-:*:*:*:*:*:*", "matchCriteriaId": "41E47F32-BA80-4333-96FD-4D25082B0FDD"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*", "matchCriteriaId": "056BD938-0A27-4569-B391-30578B309EE3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*", "matchCriteriaId": "F02056A5-B362-4370-9FF8-6F0BD384D520"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:*", "matchCriteriaId": "62075ACE-B2A0-4B16-829D-B3DA5AE5CC41"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:*", "matchCriteriaId": "A780F817-2A77-4130-A9B7-5C25606314E3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:*", "matchCriteriaId": "AEB9199B-AB8F-4877-8964-E2BA95B5F15C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.8:rc7:*:*:*:*:*:*", "matchCriteriaId": "C9B8A5CE-6D20-4C36-AC01-ACA4B70003A8"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/14f66f44646333d2bfd7ece36585874fd72f8286", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/1d731e512134495e0ef490ade0e4d91dc0d515ec", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/7c9ce68192eef14c777cb6ce17155d2eb2431aea", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c854ab481ece4b3e5f4c2e8b22824f015ff874a5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c99e160938b627f6f28edee930e8abc157e84386", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}