CVE-2026-10046: Out-of-bounds write in Napoca BIOS INT 0x15 E820 memory map handler (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

Bitdefender Napoca bare-metal hypervisor contains an out-of-bounds write vulnerability in the BIOS INT 0x15 / E820 memory map handler, implemented in napoca/guests/bios_handlers.c. The handler computes a destination offset into the guest RealModeMemory buffer from guest-controlled ES and EDI register values without validating that the resulting address remains within the 1MB RealModeMemory allocation. A malicious guest operating in real mode can trigger the issue by invoking INT 0x15 with AX=0xE820, EDX=0x534D4150, ECX greater than or equal to 20, EBX=0, ES=0xFFFF, and EDI=0xFFFF. This can cause a write of up to 20 bytes past the end of the RealModeMemory 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/consumer/support/security-advisories/out-of-bounds-write-in-napoca-bios-int-0x15-e820-memory-map-handler-va-13905

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