Integer overflow in simdjson
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
An integer overflow vulnerability in the simdjson document-builder API allows incorrect buffer size calculations in "string_builder::escape_and_append()" when processing very large input strings on platforms with limited "size_t" width (e.g., 32-bit builds). The overflow can cause insufficient buffer allocation, leading to out-of-bounds memory reads in SIMD routines and potentially resulting in information disclosure, memory corruption, or malformed JSON output. This vulnerability has been fixed in 4.6.4 release
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA simdjson (simdjson) Fixed in 4.6.4
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 1 product
- Red Hat Advanced Cluster Management for Kubernetes 2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-8295
- 2026-10-03 Alias added: GHSA-fh2w-3fv3-7vw2
References
Sources
- CVE-2026-8295 · CVE Program
- CVE-2026-8295 · NVD
- FIRST EPSS
- GHSA-fh2w-3fv3-7vw2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-8295 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences