CVE-2026-11835

MEDIUMPre-NVD 5.65.6—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.6 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 99% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:caliptra, epss
5.6EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.6Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
5.6
EG Score
5.6(medium)
EG Risk
25(Track)
EG Risk 25/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity56% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
1%
KEV
Not listed

Published

August 4, 2026

Last Modified

August 4, 2026

Advisory Details (1)

Auto-updated Aug 4, 2026
Patch available. Sources: github.
github Patch Available

Caliptra Update-Reset Secure-Boot Bypass via Attacker-Chosen AXI Staging Address (TOCTOU) · Advisory · chipsalliance/caliptra-sw · GitHub

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

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 33× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 01:21 UTCEPSS rescore
  2. 2026-08-29 21:53 UTCEG score recompute
  3. 2026-08-28 21:40 UTCEPSS rescore
  4. 2026-08-27 14:24 UTCEPSS rescore
  5. 2026-08-27 12:05 UTCEG score recompute
  6. 2026-08-26 10:17 UTCEG score recompute
  7. 2026-08-25 13:48 UTCEPSS rescore
  8. 2026-08-25 08:29 UTCEG score recompute
  9. 2026-08-23 04:51 UTCEG score recompute
  10. 2026-08-23 00:19 UTCEPSS rescore
  11. 2026-08-21 01:17 UTCEG score recompute
  12. 2026-08-20 22:55 UTCEPSS rescore
  13. 2026-08-18 21:43 UTCEG score recompute
  14. 2026-08-18 13:48 UTCEPSS rescore
  15. 2026-08-17 19:35 UTCEG score recompute
  16. 2026-08-16 17:19 UTCEG score recompute
  17. 2026-08-16 02:14 UTCEPSS rescore
  18. 2026-08-15 15:31 UTCEG score recompute
  19. 2026-08-15 01:30 UTCEPSS rescore
  20. 2026-08-12 10:11 UTCEG score recompute
  21. 2026-08-11 13:42 UTCEPSS rescore
  22. 2026-08-09 04:50 UTCEG score recompute
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-08 03:04 UTCEG score recompute
  25. 2026-08-05 23:31 UTCEG score recompute
Show 8 more
  1. 2026-08-05 19:17 UTCEPSS rescore
  2. 2026-08-04 21:45 UTCEG score recompute
  3. 2026-08-04 20:33 UTCEG score recompute
  4. 2026-08-04 19:31 UTCEG score recompute
  5. 2026-08-04 15:09 UTCEPSS rescore
  6. 2026-08-04 00:24 UTCEG score recompute
  7. 2026-08-04 00:13 UTCEG score recompute
  8. 2026-08-04 00:13 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-11835?
CVE-2026-11835 is a medium vulnerability published on August 4, 2026. 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…
When was CVE-2026-11835 disclosed?
CVE-2026-11835 was first published in the National Vulnerability Database on August 4, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11835 actively exploited?
CVE-2026-11835 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 98.6% of all scored CVEs.
What is the CVSS score of CVE-2026-11835?
CVE-2026-11835 has a CVSS v4.0 base score of 5.6 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-11835?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11835, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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