CVE-2026-43820CWE-125

CVE-2026-43820

High · published July 23, 2026

CVSS v3.1
7.7
EPSS
0%
Percentile
1.2
In the wild
Unconfirmed
What it is

NIOSSLCertificate._subjectAlternativeNames provides access to the raw bytes for a cert's SANs. NIOSSL provides access to a buffer assumed to be backed by an ASN1_STRING, but not all SANs are backed by ASN1_STRING, so accessing the buffer for such a type can lead to out-of-bounds memory access. This vulnerability is addressed in swift-nio-ssl version 2.37.2.

The record
Technical detail
CVSS v3.1
7.7 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00109 · 1.2th percentile
Weakness
CWE-125 · Out-of-bounds Read
Published
2026-07-23T19:17Z
Affected products (1)
ProductVersionsFixed in
apple/swiftnio_ssl≥ 2.18.0, < 2.37.22.37.2
References (2)
https://github.com/apple/swift-nio-ssl/security/advisories/GHSA-xfxg-9975-pc2j · [email protected]https://github.com/apple/swift-nio-ssl/security/advisories/GHSA-xfxg-9975-pc2j · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 23 JUL 14:33Z
    NIOSSLCertificate._subjectAlternativeNames provides access to the raw bytes for a cert's SANs
    cvelistv5