CVE-2026-10047: Out-of-bounds write in Napoca real-mode hook handler via guest-controlled SS:SP (VA-13905)

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-02 · updated 2026-07-22
Weakness: CWE-787

Description

The Bitdefender Napoca bare-metal hypervisor contains an out-of-bounds write vulnerability in the real-mode hook handler, implemented in napoca/kernel/handler.c. The handler uses a guest-controlled SS:SP-derived offset as an index into the 1MB RealModeMemory buffer without bounds validation. With SS=0xFFFF and ESP=0xFFFF, the computed offset can reach 0x10FFEF, exceeding the RealModeMemory buffer by 65,519 bytes. The IRET frame push can therefore write past the end of the buffer into the hypervisor heap. The product is end-of-life and unsupported when assigned.

Affected products

Bitdefender Napoca bare-metal hypervisor: all versions

References

https://www.bitdefender.com/support/security-advisories/out-of-bounds-write-in-napoca-real-mode-hook-handler-via-guest-controlled-sssp-va-13905

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