Is CVE-2021-26957 actively exploited?

No active exploitation of CVE-2021-26957 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-26957 be exploited remotely?

Yes. CVE-2021-26957 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-26957?

CVE-2021-26957 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-26957

CRITICAL

CVE-2021-26957

CWE-125Published: February 9, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

An issue was discovered in the xcb crate through 2021-02-04 for Rust. It has a soundness violation because there is an out-of-bounds read in xcb::xproto::change_property(), as demonstrated by a format=32 T=u8 situation where out-of-bounds bytes are sent to an X server.

NVD Source

Technical Analysis

CVE-2021-26957 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.