CVE-2026-49263
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-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.
Scoring
- Severity
- LOW
- CVSS base score
- 2
- CVSS vector
- CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- EPSS probability
- 0.13%
- CWE
- CWE-197
- Published
- 2026-08-14
- Last modified
- 2026-08-17
Affected products
- capstone-engine capstone
Weakness type
Related vulnerabilities
- CVE-2026-87529 — Numeric truncation error in Media in Google Chrome prior to 153.0.8010.36 allowed a remote attacker...
- CVE-2026-78512 — Microsoft Office Word Remote Code Execution Vulnerability
- CVE-2026-69535 — Windows Spaceport.sys Elevation of Privilege Vulnerability
- CVE-2026-69512 — Windows Spaceport.sys Elevation of Privilege Vulnerability
- CVE-2026-69578 — Windows Kernel Elevation of Privilege Vulnerability
- CVE-2026-68895 — Internet Storage Name Service Information Disclosure Vulnerability
- CVE-2026-68880 — Windows Win32k Elevation of Privilege Vulnerability
- CVE-2026-69822 — Windows Kerberos Elevation of Privilege Vulnerability