CVE-2026-23442

/* * PoC Concept for CVE-2026-23442 * This is a conceptual demonstration. Triggering requires a specific kernel environment. * Logic: Attempt to trigger SRv6 processing on an interface with invalid IPv6 config. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <linux/if.h> #include <arpa/inet.h> int main() { // Note: Actual exploitation requires setting up a network interface // with MTU < IPV6_MIN_MTU (e.g., 1200) and sending SRv6 traffic. // This code simulates the user-space part of sending crafted traffic. int sockfd; struct sockaddr_in6 addr; sockfd = socket(AF_INET6, SOCK_RAW, IPPROTO_RAW); if (sockfd < 0) { perror("socket"); return 1; } // Target a local interface (assumed to be configured or misconfigured) memset(&addr, 0, sizeof(addr)); addr.sin6_family = AF_INET6; inet_pton(AF_INET6, "::1", &addr.sin6_addr); // In a real exploit, one would craft a packet with Segment Routing Header (SRH) // to trigger ipv6_srh_rcv() or seg6_hmac_validate_skb(). // The vulnerability triggers if the interface has no valid IPv6 config (idev is NULL). printf("Sending crafted packet to trigger potential NULL pointer dereference...\n"); // sendto(sockfd, buffer, len, 0, (struct sockaddr*)&addr, sizeof(addr)); close(sockfd); return 0; }

{"cve": {"id": "CVE-2026-23442", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-03T16:16:28.423", "lastModified": "2026-04-27T14:16:33.030", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: add NULL checks for idev in SRv6 paths\n\n__in6_dev_get() can return NULL when the device has no IPv6 configuration\n(e.g. MTU < IPV6_MIN_MTU or after NETDEV_UNREGISTER).\n\nAdd NULL checks for idev returned by __in6_dev_get() in both\nseg6_hmac_validate_skb() and ipv6_srh_rcv() to prevent potential NULL\npointer dereferences."}], "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": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10.1", "versionEndExcluding": "6.12.83", "matchCriteriaId": "C9FB8914-AA64-42C8-B1C5-31091B1EAA92"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.19.10", "matchCriteriaId": "74050944-3704-4081-A5DA-C5DAB1E275E6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:4.10:-:*:*:*:*:*:*", "matchCriteriaId": "C201E405-86F2-4F96-984A-00A865219C86"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/06413793526251870e20402c39930804f14d59c0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/50352fc103928e10e8729abc79a0d05abef26c4d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a25853c9feea7bbf31d157ff6e004d2d3b4f7f13", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/bc9843c39f9932a8b36efd1d362ea00bb88e4e78", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/c5cedee5d97382176573bbe21e1724e737a5eb64", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}]}}