CVE-2026-49263Capstone WASM `br_table` instruction-size truncation can cause no-progress disassembly and parser desynchronization
Updated under an hour ago ()
Does this affect you?
It affects capstone-engine capstone. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 2.0 LOW (v4.0, CNA)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
- Weakness (CWE)
- CWE-197
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Aug 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
capstone-engine capstone capstone_engine:capstone (from the name) | before 6.0.0-Alpha9 | CNA record |
References
- https://github.com/capstone-engine/capstone/security/advisories/GHSA-5m9f-vqcm-g5prx-refsource-confirm
- https://github.com/capstone-engine/capstone/blob/251c5bb4bc9bb92973e738ae3c5f4ef86f103356/ChangeLog#L102x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.