AMD confidential computing - DDR5 memory bus interposition against TEEs: Compromising trusted execution environments by

Impact

Compromising trusted execution environments by interposing on the DDR5 memory bus. Same family as the BadRAM interposer work and the same conclusion for an operator: SEV-SNP's guarantees are software- and firmware-scoped, and an adversary with hands on the hardware sits outside them.

Who can reach it

Physical access with DDR5 bus interposition hardware.

What to do

**No patch** - physical attacks fall outside the declared SEV-SNP threat model. Mitigation is datacenter physical security, hardware chain of custody, and honest scoping of what confidential computing does and does not promise your tenants.

References

Related entries

• DMTF libspdm (GET_MEASUREMENT_EXTENSION_LOG offset/length wrap): Wrapping addition of the Offset and Length fieldsNCVD-2026-001-dmtf-libspdm-get-measurement-ext · DMTF libspdm (GET_MEASUREMENT_EXTENSION_LOG offset/length wrap)Unscored
• Linux Safe RET SRSO mitigation on AMD Zen 1-Zen 4 - interrupt-induced weakening: An attacker executing code on theNCVD-2026-001-linux-safe-ret-srso-mitigation-o · Linux Safe RET SRSO mitigation on AMD Zen 1-Zen 4 - interrupt-induced weakeningUnscored
• DMTF libspdm (cryptlib_mbedtls CSR generation, stack overflow): An over-long Common Name in a GET_CSR request writesNCVD-2026-002-dmtf-libspdm-cryptlib-mbedtls-cs · DMTF libspdm (cryptlib_mbedtls CSR generation, stack overflow)Unscored
• AMD - REP-string execution unit scheduler contention side channel: A newer variant of the SQUIP scheduler-contentionNCVD-2026-003-amd-rep-string-execution-unit-sc · AMD - REP-string execution unit scheduler contention side channelUnscored
• Das U-Boot (FIT image signature verification): Binarly disclosed a cluster of flaws in U-Boot's FIT image handlingNCVD-2026-005-das-u-boot-fit-image-signature-v · Das U-Boot (FIT image signature verification)Unscored
• WEKA Data Platform and VAST Data (published-advisory coverage): Neither WEKA nor VAST DataNCVD-2026-014-weka-data-platform-and-vast-data · WEKA Data Platform and VAST Data (published-advisory coverage)Unscored