# CVE-2026-18448: EDK2 SMRAM information disclosure during transient execution

Source: https://junglewise.ai/threats/cve-2026-18448-edk2-contains-a-vulnerability-in-bios-where-a-privileged-attacker  
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-2026-18448 · Severity: info · Published 2026-11-10

EDK2 is a firmware framework used in BIOS and UEFI implementations on AMD platforms. A privileged local attacker can exploit insufficient mitigations against Transient Scheduler Attacks to read sensitive data from System Management RAM (SMRAM), bypassing the isolation that protects the most critical firmware code. This disclosure could expose cryptographic keys, security policies, or other confidential data stored in protected memory.

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

## Quick answers

**Is CVE-2026-18448 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18448 being exploited in the wild.

**How severe is CVE-2026-18448?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Tianocore Edk2 9a36d4dc3f5ec6a4e134198329883df8bf43634f and earlier.

**Is there a fix for CVE-2026-18448?** 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-2026-18448 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-18448?** 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 exists in UefiCpuPkg's insufficient TSA (Transient Scheduler Attack) mitigations, allowing a ring-0 attacker to infer residual microarchitectural state left by SMM (System Management Mode) execution to read SMRAM contents. Attack vector is local with high attack complexity; requires privileged access and the presence of specific microarchitectural conditions on AMD systems. A proof-of-concept exists but the advisory states no patched versions are available as of publication.

## Affected products

- tianocore EDK2 9a36d4dc3f5ec6a4e134198329883df8bf43634f and earlier

## Timeline

- 2026-11-10: disclosed

## References

- [https://github.com/tianocore/edk2/security/advisories/GHSA-7v86-66vf-h88j](https://github.com/tianocore/edk2/security/advisories/GHSA-7v86-66vf-h88j)

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