{"id":"JLSEC-2026-727","summary":"An integer overflow existed in the wolfCrypt CMAC implementation, that could be exploited to forge...","details":"An integer overflow existed in the wolfCrypt CMAC implementation, that could be exploited to forge CMAC tags. The function `wc_CmacUpdate` used the guard `if (cmac-\u003etotalSz != 0)` to skip XOR-chaining on the first block (where digest is all-zeros and the XOR is a no-op). However, totalSz is word32 and wraps to zero after 2^28 block flushes (4 GiB), causing the guard to erroneously discard the live CBC-MAC chain state. Any two messages sharing a common suffix beyond the 4 GiB mark then produce identical CMAC tags, enabling a zero-work prefix-substitution forgery. The fix removes the guard, making the XOR unconditional; the no-op property on the first block is preserved because digest is zero-initialized by `wc_InitCmac_ex`.","modified":"2026-07-25T18:24:49.566015353Z","published":"2026-07-14T21:41:35.775Z","upstream":["CVE-2026-5477","GHSA-grqc-3vmg-p68x","EUVD-2026-21305"],"database_specific":{"license":"CC-BY-4.0","sources":[{"published":"2026-04-10T06:16:05.243Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-5477","html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5477","database_specific":{"status":"Analyzed"},"id":"CVE-2026-5477","imported":"2026-07-17T22:31:41.012Z","modified":"2026-06-17T10:59:06.143Z"},{"url":"https://api.github.com/advisories/GHSA-grqc-3vmg-p68x","html_url":"https://github.com/advisories/GHSA-grqc-3vmg-p68x","id":"GHSA-grqc-3vmg-p68x","imported":"2026-07-17T22:31:41.164Z","modified":"2026-04-27T18:33:06Z","published":"2026-04-10T06:31:38Z"},{"imported":"2026-07-17T22:31:51.078Z","modified":"2026-04-10T14:04:00Z","published":"2026-04-10T05:06:22Z","url":"https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-21305","html_url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-21305","id":"EUVD-2026-21305"}]},"references":[{"type":"WEB","url":"https://github.com/advisories/GHSA-grqc-3vmg-p68x"},{"type":"WEB","url":"https://github.com/wolfSSL/wolfssl/pull/10102"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5477"}],"affected":[{"package":{"name":"wolfSSL_jll","ecosystem":"Julia","purl":"pkg:julia/wolfSSL_jll?uuid=98c43586-9870-5ae5-ab22-acc77b9bbdb5"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.9.2+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-727.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}