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
History

Fri, 15 May 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

threat_severity

Moderate


Thu, 14 May 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 14 May 2026 14:00:00 +0000

Type Values Removed Values Added
First Time appeared Simdjson Project
Simdjson Project simdjson
Vendors & Products Simdjson Project
Simdjson Project simdjson

Thu, 14 May 2026 10:45:00 +0000

Type Values Removed Values Added
Description 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
Title Integer overflow in simdjson
Weaknesses CWE-190
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: CERT-PL

Published:

Updated: 2026-05-14T17:48:38.036Z

Reserved: 2026-05-11T09:30:25.123Z

Link: CVE-2026-8295

cve-icon Vulnrichment

Updated: 2026-05-14T17:48:32.073Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-14T11:16:18.770

Modified: 2026-05-14T16:04:49.770

Link: CVE-2026-8295

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-14T10:27:41Z

Links: CVE-2026-8295 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-14T13:45:18Z