# CVE-2026-14968: EDK2 MmSaveStateLib out-of-bounds write in AMD SysCall path

Source: https://junglewise.ai/threats/cve-2026-14968-edk2-contains-vulnerabilities-in-bios-where-skilled-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-14968 · Severity: info · Published 2026-11-10

EDK2 is firmware code used in BIOS/UEFI implementations on AMD systems. A flaw in the AMD save-state library causes writes beyond the requested size when reading CPU registers, potentially corrupting system memory and compromising the security manager mode (SMM) firmware that runs with the highest privilege. This could lead to denial of service, system instability, or bypass of firmware security controls.

Technologies: [Tianocore Edk2](https://junglewise.ai/threats/technologies/edk2). Vendors: [Tianocore](https://junglewise.ai/threats/vendors/tianocore).

## Quick answers

**Is CVE-2026-14968 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-14968 being exploited in the wild.

**How severe is CVE-2026-14968?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Tianocore Edk2 commit 64b62a08797295b2f5b6a394866be5533d3507d2 and later.

**Is there a fix for CVE-2026-14968?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-14968 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-14968?** Check whether you run Tianocore Edk2 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an out-of-bounds write in UefiCpuPkg/Library/MmSaveStateLib/AmdMmSaveState.c in the MmSaveStateReadRegisterByIndex() function. When the SysCall path is enabled and a partial-width register read is requested (1–3 bytes or 5–7 bytes), the code writes full 32-bit values into the caller buffer instead of respecting the requested byte count, corrupting adjacent SMM/MM memory. This affects AMD platforms where AmdSysCallLib is configured with a non-null implementation and requires local privileged access to trigger.

## Affected products

- TianoCore EDK2 commit 64b62a08797295b2f5b6a394866be5533d3507d2 and later

## Timeline

- 2026-11-03: disclosed: GitHub security advisory published
- 2026-11-10: advisory: NVD entry created

## References

- [https://github.com/tianocore/edk2/security/advisories/GHSA-979r-6wfh-gq4h](https://github.com/tianocore/edk2/security/advisories/GHSA-979r-6wfh-gq4h)

## Related threats

- [EDK2 SMRAM information disclosure during transient execution](https://junglewise.ai/threats/cve-2026-18448-edk2-contains-a-vulnerability-in-bios-where-a-privileged-attacker)
- [EDK2 buffer overflow in PXE driver pre-boot RCE](https://junglewise.ai/threats/cve-2026-97631-edk2-contains-a-vulnerability-in-bios-where-a-user-may-cause-out)
- [The Ubuntu edk2 UEFI firmware packages accidentally allowed the UEFI Shell to be accessed in Secure Boot environments…](https://junglewise.ai/threats/cve-2025-2486-the-ubuntu-edk2-uefi-firmware-packages-accidentally-allowed-the)