What is CVE-2023-53159?

CVE-2023-53159 is a medium-severity vulnerability in Sfackler OpenSSL, classified under Buffer Over-read. CVSS score: 4.5/10. Published 2025-07-28.

How severe is CVE-2023-53159?

Medium severity. CVSS v3 base score is 4.5 out of 10.

Vulnerability in Sfackler OpenSSL

CVE-2023-53159

The openssl crate before 0.10.55 for Rust allows an out-of-bounds read via an empty string to X509VerifyParamRef::set_host.

Published 2025-07-28 · last modified 2026-09-17.

CVSS v3 metric

CVSS v3 base score 4.5 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L.

EPSS exploit prediction

EPSS: 0.002 (8.8th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.002 · change: -0.001

Affected products

Sfackler OpenSSL — versions 0

Weakness classification (CWE)

CWE-126 — Buffer Over-read

References

rustsec.org/advisories/RUSTSEC-2023-0044.html (Third Party Advisory)
github.com/sfackler/rust-openssl/issues/1965 (Exploit, Patch)
crates.io/crates/openssl (Product)

Frequently asked questions

What is CVE-2023-53159?: CVE-2023-53159 is a medium-severity vulnerability in Sfackler OpenSSL, classified under Buffer Over-read. CVSS score: 4.5/10. Published 2025-07-28.
How severe is CVE-2023-53159?: Medium severity. CVSS v3 base score is 4.5 out of 10.