{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-11835","assignerOrgId":"b01ddd03-5ef6-483b-b2c5-acba77f1a554","state":"PUBLISHED","assignerShortName":"Caliptra","dateReserved":"2026-06-09T23:30:36.611Z","datePublished":"2026-08-04T00:03:23.278Z","dateUpdated":"2026-08-04T21:25:26.656Z"},"containers":{"cna":{"providerMetadata":{"orgId":"b01ddd03-5ef6-483b-b2c5-acba77f1a554","shortName":"Caliptra","dateUpdated":"2026-08-04T21:25:26.656Z"},"title":"Caliptra Update-Reset Secure-Boot Bypass via Attacker-Chosen AXI Staging Address (TOCTOU)","datePublic":"2026-08-03T00:00:00.000Z","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-367","description":"CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-20","description":"CWE-20 Improper Input Validation","type":"CWE"}]}],"impacts":[{"capecId":"CAPEC-29","descriptions":[{"lang":"en","value":"CAPEC-29 Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions"}]}],"affected":[{"vendor":"Caliptra","product":"Core ROM","collectionURL":"https://github.com/chipsalliance/caliptra-sw","packageName":"Core ROM","modules":["UpdateResetFlow::run()"],"versions":[{"status":"affected","version":"2.1.0","lessThanOrEqual":"2.1.1","versionType":"semver"},{"status":"unaffected","version":"2.1.2","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"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.\n\nThis issue affects Core ROM: 2.1.0 through 2.1.1.","supportingMedia":[{"type":"text/html","base64":false,"value":"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.<p>This issue affects Core ROM: 2.1.0 through 2.1.1.</p>"}]}],"tags":["x_open-source"],"references":[{"url":"https://github.com/chipsalliance/caliptra-sw/security/advisories/GHSA-49mm-5gq5-v97f"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"MEDIUM","baseScore":5.6,"vectorString":"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"}}],"credits":[{"lang":"en","value":"Alex Matrosov with Claude, Anthropic","type":"finder"}],"source":{"discovery":"INTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-04T19:21:52.034967Z","id":"CVE-2026-11835","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-04T19:24:22.359Z"}}]}}