CVE-2026-49263

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Source
https://cve.org/CVERecord?id=CVE-2026-49263
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49263.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-49263
Aliases
  • GHSA-5m9f-vqcm-g5pr
Downstream
Published
2026-08-14T17:49:36.804Z
Modified
2026-08-16T03:48:30.530597089Z
Severity
  • 2.0 (Low) CVSS_V4 - 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 CVSS Calculator
Summary
Capstone WASM `br_table` instruction-size truncation can cause no-progress disassembly and parser desynchronization
Details

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.

Database specific 
{
    "cwe_ids": [
        "CWE-197"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49263.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/capstone-engine/capstone

Affected ranges

Type
GIT
Repo
https://github.com/capstone-engine/capstone
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
973b9096dd82c4efb4d7ba3d95a0e2b73243d3ba
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "6.0.0-Alpha9"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

1.*
1.0
2.*
2.0
2.0-rc1
2.1
3.*
3.0-rc1
3.0-rc2
3.0-rc3
4.*
4.0-alpha1
4.0-alpha2
6.*
6.0.0-Alpha3
6.0.0-Alpha4
6.0.0-Alpha5
6.0.0-Alpha6
6.0.0-Alpha7
6.0.0-Alpha8

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49263.json"