CVE Explorer
CVE-2026-40097
Step CA is an online certificate authority for secure, automated certificate management for DevOps. From 0.24.0 to before 0.30.0-rc3, an attacker can trigger an index out-of-bounds panic in Step CA by sending a crafted attestation key (AK) certificate with an empty Extended Key Usage (EKU) extension during TPM device attestation. When processing a device-attest-01 ACME challenge using TPM attestation, Step CA validates that the AK certificate contains the tcg-kp-AIKCertificate Extended Key Usage
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"certificates","vendor":"smallstep","versions":[{"status":"affected","version":">= 0.24.0, < 0.30.0-rc3"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:4abb24db400f66eb129e38c980fe7245e1ac196c65052aefb90ebca44b287680 · sha256:cbd071bd4a16a794… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":3.7,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:4abb24db400f66eb129e38c980fe7245e1ac196c65052aefb90ebca44b287680 · sha256:cbd071bd4a16a794… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-129","description":"CWE-129: Improper Validation of Array Index","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:4abb24db400f66eb129e38c980fe7245e1ac196c65052aefb90ebca44b287680 · sha256:cbd071bd4a16a794… · /containers/cna/problemTypes/0/descriptions/0
Source references
4 source assertions{"name":"https://github.com/smallstep/certificates/commit/ffd31ac0a87e03b0224cb8363094bfe602242888","tags":["x_refsource_MISC"],"url":"https://github.com/smallstep/certificates/commit/ffd31ac0a87e03b0224cb8363094bfe602242888"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4abb24db400f66eb129e38c980fe7245e1ac196c65052aefb90ebca44b287680 · sha256:cbd071bd4a16a794… · /containers/cna/references/2
{"name":"https://github.com/smallstep/certificates/pull/2569","tags":["x_refsource_MISC"],"url":"https://github.com/smallstep/certificates/pull/2569"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4abb24db400f66eb129e38c980fe7245e1ac196c65052aefb90ebca44b287680 · sha256:cbd071bd4a16a794… · /containers/cna/references/1
{"name":"https://github.com/smallstep/certificates/releases/tag/v0.30.0","tags":["x_refsource_MISC"],"url":"https://github.com/smallstep/certificates/releases/tag/v0.30.0"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4abb24db400f66eb129e38c980fe7245e1ac196c65052aefb90ebca44b287680 · sha256:cbd071bd4a16a794… · /containers/cna/references/3
{"name":"https://github.com/smallstep/certificates/security/advisories/GHSA-9qq8-cgcv-qmc9","tags":["x_refsource_CONFIRM"],"url":"https://github.com/smallstep/certificates/security/advisories/GHSA-9qq8-cgcv-qmc9"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4abb24db400f66eb129e38c980fe7245e1ac196c65052aefb90ebca44b287680 · sha256:cbd071bd4a16a794… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.