CVE-2026-28386 (GCVE-0-2026-28386)

Vulnerability from cvelistv5 – Published: 2026-04-07 22:00 – Updated: 2026-04-10 20:16
VLAI?
Title
Out-of-bounds Read in AES-CFB-128 on X86-64 with AVX-512 Support
Summary
Issue summary: Applications using AES-CFB128 encryption or decryption on systems with AVX-512 and VAES support can trigger an out-of-bounds read of up to 15 bytes when processing partial cipher blocks. Impact summary: This out-of-bounds read may trigger a crash which leads to Denial of Service for an application if the input buffer ends at a memory page boundary and the following page is unmapped. There is no information disclosure as the over-read bytes are not written to output. The vulnerable code path is only reached when processing partial blocks (when a previous call left an incomplete block and the current call provides fewer bytes than needed to complete it). Additionally, the input buffer must be positioned at a page boundary with the following page unmapped. CFB mode is not used in TLS/DTLS protocols, which use CBC, GCM, CCM, or ChaCha20-Poly1305 instead. For these reasons the issue was assessed as Low severity according to our Security Policy. Only x86-64 systems with AVX-512 and VAES instruction support are affected. Other architectures and systems without VAES support use different code paths that are not affected. OpenSSL FIPS module in 3.6 version is affected by this issue.
Severity ?
No CVSS data available.
CWE
Assigner
References
Impacted products
Vendor Product Version
OpenSSL OpenSSL Affected: 3.6.0 , < 3.6.2 (semver)
Create a notification for this product.
Date Public ?
2026-04-07 14:00
Credits
Stanislav Fort (Aisle Research) Pavel Kohout (Aisle Research) Alex Gaynor (Anthropic) Stanislav Fort (Aisle Research) Pavel Kohout (Aisle Research) Alex Gaynor (Anthropic)
Show details on NVD website
To clipboard 

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Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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