CVE-2026-33666
Zserio: Integer Overflow in BitStreamReader on 32-bit platforms
Description
Zserio is a framework for serializing structured data with a compact and efficient way with low overhead. Prior to 2.18.1, in BitStreamReader.h readBytes() / readString(), the setBitPosition() bounds check receives the overflowed value and is completely bypassed. The code then reads len bytes (512 MB) from a buffer that is only a few bytes long, causing a segmentation fault. This vulnerability is fixed in 2.18.1.
INFO
Published Date :
April 24, 2026, 7:17 p.m.
Last Modified :
April 24, 2026, 7:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-33666
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 3.1 | HIGH | [email protected] |
Solution
- Update Zserio to version 2.18.1.
- Review BitStreamReader.h for setBitPosition() bounds checks.
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-2026-33666.
| URL | Resource |
|---|---|
| https://github.com/ndsev/zserio/security/advisories/GHSA-fjwv-6wcr-vqwj |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-33666 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-2026-33666
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-2026-33666 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-33666 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]
Apr. 24, 2026
Action Type Old Value New Value Added Description Zserio is a framework for serializing structured data with a compact and efficient way with low overhead. Prior to 2.18.1, in BitStreamReader.h readBytes() / readString(), the setBitPosition() bounds check receives the overflowed value and is completely bypassed. The code then reads len bytes (512 MB) from a buffer that is only a few bytes long, causing a segmentation fault. This vulnerability is fixed in 2.18.1. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-190 Added Reference https://github.com/ndsev/zserio/security/advisories/GHSA-fjwv-6wcr-vqwj