CVE-2026-43453

/* * Conceptual PoC for CVE-2026-43453 * Triggering the stack out-of-bounds read in pipapo_drop(). */ #include <stdio.h> // Note: This vulnerability is within the Linux Kernel (netfilter). // It requires a specific kernel version and local access to trigger. // The following steps describe the logic to reproduce: // // 1. Load the nf_tables module. // 2. Create an nftables table. // 3. Create a 'set' with type 'pipapo' (e.g., for IPv4 addresses). // 4. Populate the set such that the internal structure utilizes NFT_PIPAPO_MAX_FIELDS. // 5. Perform a deletion operation on the set or elements to invoke pipapo_drop(). // 6. Monitor kernel logs for KASAN report: // "BUG: KASAN: stack-out-of-bounds in pipapo_drop+0x50c/0x57c [nf_tables]" int main() { printf("To test this CVE, run the following commands on a vulnerable kernel:\n"); printf("1. nft add table ip filter\n"); printf("2. nft add set ip filter my_set { type ipv4_addr; flags interval; }\n"); printf("3. [Manipulate set to reach max fields/complexity]\n"); printf("4. nft delete set ip filter my_set\n"); printf("5. Check dmesg for out-of-bounds read.\n"); return 0; }

{"cve": {"id": "CVE-2026-43453", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-08T15:16:58.027", "lastModified": "2026-05-21T16:52:05.013", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop()\n\npipapo_drop() passes rulemap[i + 1].n to pipapo_unmap() as the\nto_offset argument on every iteration, including the last one where\ni == m->field_count - 1. This reads one element past the end of the\nstack-allocated rulemap array (declared as rulemap[NFT_PIPAPO_MAX_FIELDS]\nwith NFT_PIPAPO_MAX_FIELDS == 16).\n\nAlthough pipapo_unmap() returns early when is_last is true without\nusing the to_offset value, the argument is evaluated at the call site\nbefore the function body executes, making this a genuine out-of-bounds\nstack read confirmed by KASAN:\n\n BUG: KASAN: stack-out-of-bounds in pipapo_drop+0x50c/0x57c [nf_tables]\n Read of size 4 at addr ffff8000810e71a4\n\n This frame has 1 object:\n [32, 160) 'rulemap'\n\n The buggy address is at offset 164 -- exactly 4 bytes past the end\n of the rulemap array.\n\nPass 0 instead of rulemap[i + 1].n on the last iteration to avoid\nthe out-of-bounds read."}], "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:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.10.253", "matchCriteriaId": "A46EE847-2B8F-4145-AB46-8D057B48AFC9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.203", "matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.167", "matchCriteriaId": "2EDC6BAF-B710-4E26-B6AA-D68922EE7B43"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.130", "matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.78", "matchCriteriaId": "28D591F5-B196-4CC9-905C-DC80F116E7A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.19", "matchCriteriaId": "D394AC60-6F28-435F-872A-CCDF384B8331"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.9", "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9"}, {"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"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0a55d62cdb628923d8a21724374a70c76ac7d19d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/1957e793196e7f8557374fd4eda53abcbb42e1c0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/324b749aa5b2d516ccfab933df9d3f56e7807f5f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/57fb87ca095d5127cd7a27583b8ec43dcf7c9e9e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/60c1d18781e37bfb96290b86510eb01c5fa24d75", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d6d8cd2db236a9dd13dbc2d05843b3445cc964b5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/dfbdac719198778b581bc0dd055df2542edb8c62", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {" ... (truncated)