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
References (2)
Core 2
Core References
Release Notes release-notes
https://github.com/simdjson/simdjson/releases/tag/v4.6.4
Third Party Advisory third-party-advisory
https://cert.pl/posts/2026/05/CVE-2026-8295
Scores
CVSS v4
6.9
EPSS
0.0028
EPSS Percentile
19.4%
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-190
Status
published
Products (1)
simdjson/simdjson
< 4.6.4
Published
May 14, 2026
Tracked Since
May 14, 2026