CVE-2026-8295
Integer overflow in simdjson
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
INFO
Published Date :
May 14, 2026, 11:16 a.m.
Last Modified :
May 14, 2026, 11:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-8295
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update simdjson library to version 4.6.4.
- Ensure platform size_t width is sufficient.
- Rebuild affected applications.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-8295.
| URL | Resource |
|---|---|
| https://cert.pl/posts/2026/05/CVE-2026-8295 | |
| https://github.com/simdjson/simdjson/releases/tag/v4.6.4 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-8295 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-8295
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-8295 vulnerability anywhere in the article.
-
cert.pl
Vulnerability in simdjson library
Vulnerability in simdjson library CVE ID CVE-2026-8295 Publication date 14 May 2026 Vendor simdjson Product simdjson Vulnerable versions All before 4.6.4 Vulnerability type (CWE) Integer Overflow or W ... Read more
The following table lists the changes that have been made to the
CVE-2026-8295 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
May. 14, 2026
Action Type Old Value New Value 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 Added CVSS V4.0 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 Added CWE CWE-190 Added Reference https://cert.pl/posts/2026/05/CVE-2026-8295 Added Reference https://github.com/simdjson/simdjson/releases/tag/v4.6.4