Memory handling issues in xcb

published 2020-12-10 5 y ago modified 2026-06-17 4 mo ago also GHSA-c8hq-x4mm-p6q6 , RUSTSEC-2020-0097 , EUVD-2021-1676

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits: 0; none known

An issue was discovered in the xcb crate through 2020-12-10 for Rust. base::Error does not have soundness. Because of the public ptr field, a use-after-free or double-free can occur.

Patch / fix

fixed in 1 distros 1

crates.io xcb 1.0.0

rust-xcb Debian 14, Debian 13, Debian 12 1.1.1-1

debian advisories DEBIAN-CVE-2020-36205

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

rustsec.org https://rustsec.org/advisories/RUSTSEC-2020-0097.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	2.1	AV:L/AC:L/Au:N/C:N/I:N/A:P
OSV	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
GitHub	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
crates.io	xcb	<1.0.0 >=0.0.0-0, <1.0.0	1.0.0

Classification

Weakness

CWE-415 Double Free
CWE-416 Use After Free

References

rustsec.org /advisories/RUSTSEC-2020-0097.html
web, exploit, vendor-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2020-36205
advisory
github.com /rtbo/rust-xcb/issues/93
web
github.com /rust-x-bindings/rust-xcb/issues/93
web, report
github.com /rtbo/rust-xcb
package
crates.io /crates/xcb
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary