CVE-2026-28815
Published: 03 April 2026
Summary
CVE-2026-28815 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Apple Swift-Crypto. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 16.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SI-10 (Information Input Validation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly mandates timely patching of the out-of-bounds read flaw in swift-crypto by updating to version 4.3.1 or later.
Requires validation of HPKE encapsulated key inputs to reject short or malformed keys before decapsulation processing.
Implements runtime memory protections like ASLR and memory tagging to mitigate crashes or disclosures from the out-of-bounds read.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated OOB read in HPKE decapsulation path enables exploitation of public-facing apps (T1190) and direct DoS via application crash (T1499.004); memory disclosure is conditional and does not map to additional techniques.
NVD Description
A remote attacker can supply a short X-Wing HPKE encapsulated key and trigger an out-of-bounds read in the C decapsulation path, potentially causing a crash or memory disclosure depending on runtime protections. This issue is fixed in swift-crypto version 4.3.1.
Deeper analysisAI
CVE-2026-28815 is an out-of-bounds read vulnerability (CWE-125) in the C decapsulation path of the swift-crypto library, triggered when a remote attacker supplies a short X-Wing HPKE encapsulated key. It affects versions of swift-crypto prior to 4.3.1 and has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high availability impact with no direct confidentiality or integrity effects.
A remote, unauthenticated attacker can exploit this vulnerability by providing a maliciously crafted short encapsulated key during HPKE decapsulation, leading to an out-of-bounds read. Depending on runtime protections such as address space layout randomization or memory tagging, this may result in a denial-of-service crash or potential memory disclosure.
The official advisory on GitHub (GHSA-9m44-rr2w-ppp7) confirms the issue and states that it is fixed in swift-crypto version 4.3.1. Security practitioners should update to this version or later to mitigate the vulnerability.
Details
- CWE(s)