SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-8295

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…

MEDIUM 6.9EPSS 0.28%

Does this matter?

Lower severity and a low EPSS score (0.28%). Track it; it rarely justifies an emergency change on its own.

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

CVSS 4.0
6.9 MEDIUMCVSS: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/M
EPSS
0.28% probability · 20th percentile
CISA KEV
Not listed
Weakness
CWE-190
Source
cvd@cert.pl

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.