CVE-2021-26957
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.71%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.71% probability · 77th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- xcb project/xcb
- Source
- cve@mitre.org
EPSS 1.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://rustsec.org/advisories/RUSTSEC-2021-0019.htmlExploit, Vendor Advisory
- https://rustsec.org/advisories/RUSTSEC-2021-0019.htmlExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.