---
cve: "CVE-2026-11835"
severity: "MEDIUM"
cvss: 5.6
epss: "8%"
vendor: "Caliptra"
kev: false
exploited: false
published: "2026-08-04 00:16:40"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T13:57:28+02:00"
---

# CVE-2026-11835

> 5.6 MEDIUM · 🧪 PoC

## Beschreibung

Time-of-check time-of-use (TOCTOU) vulnerability combined with missing input validation in Caliptra Core ROM (UpdateResetFlow::run()) in subsystem mode allows a compromised local attacker to silently bypass secure boot by supplying an AXI staging address that is not validated against the strap-configured SS_EXTERNAL_STAGING_AREA_BASE_ADDR, enabling firmware to be modified between verification and loading into ICCM. Attestation continues to report the originally verified image digest, masking the compromise. Exploitation requires a compromised MCU firmware with AXI manager access to unprotected SRAM reachable by Caliptra.

This issue affects Core ROM: 2.1.0 through 2.1.1.

## CVSS-Vektor

```
CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Hoch | good |
| PR Privilegien | Hoch | good |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 510a23adbc911e8e72708799daba964ec045ef25 (Commit)

## Referenzen

- <https://github.com/chipsalliance/caliptra-sw/security/advisories/GHSA-49mm-5gq5-v97f>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-11835) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_