{"id":"CVE-2026-49263","title":"Capstone is a disassembly framework","summary":"Capstone is a disassembly framework. Prior to version 6.0.0-Alpha9, Capstone's WebAssembly backend accepts attacker-controlled raw WASM instruction bytes through the public `cs_disasm()` and `cs_disasm_iter()` APIs. For a large but well-…","severity":"medium","cwe":["CWE-197","CWE-190"],"published":"2026-08-14","updated":"2026-09-18","sourceUpdated":"2026-09-18T20:05:53.723","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-49263","references":[{"url":"https://github.com/capstone-engine/capstone/blob/251c5bb4bc9bb92973e738ae3c5f4ef86f103356/ChangeLog#L102","label":"security-advisories@github.com"},{"url":"https://github.com/capstone-engine/capstone/security/advisories/GHSA-5m9f-vqcm-g5pr","label":"security-advisories@github.com"},{"url":"https://github.com/capstone-engine/capstone/security/advisories/GHSA-5m9f-vqcm-g5pr","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49263.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-49263"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2516114"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-49263"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49263"},{"url":"https://access.redhat.com/errata/RHSA-2026:81540"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00171,"epssPercentile":0.06496,"ingestedAt":"2026-09-18T20:51:25.617Z","vendor":"Red Hat","product":"Red Hat Hardened Images","affected":["enterprise_linux 10","enterprise_linux 9","openshift_container_platform 4","hardened_images"],"patched":["hardened_images"],"cvss":6.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","cvssSource":"vendor","slug":"CVE-2026-49263","body":"## Overview\n\nCapstone is a disassembly framework. Prior to version 6.0.0-Alpha9, Capstone's WebAssembly backend accepts attacker-controlled raw WASM instruction bytes through the public `cs_disasm()` and `cs_disasm_iter()` APIs. For a large but well-formed `br_table` instruction, the WASM decoder accumulates the immediate length in a wider local variable but returns it through a `uint16_t` instruction-size path. When the encoded instruction length is exactly 65,536 bytes, the size wraps to zero and `cs_disasm()` can repeatedly decode the same instruction without advancing. For larger lengths, `cs_disasm_iter()` advances into the middle of the `br_table` payload and decodes target bytes as subsequent instructions. This is an availability and parser-integrity issue. Version 6.0.0-Alpha9 patches the issue.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:81540** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:81540)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49263.json)","depth":"sunlit","depthScore":37,"depthScoreParts":{"impact":37.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":222912,"id":"CVE-2026-49263","ts":1792151667100,"field":"cvss","old":null,"new":"6.8"},{"seq":222911,"id":"CVE-2026-49263","ts":1792151667100,"field":"severity","old":"none","new":"medium"}]}