CVE-2026-126792
Heap overflow via oversized RSA signature in GCP KMS signing callback
Published Nov 12, 2026
CVSS 4.0 · 5.6 Medium
EPSS < 1%
KEV · Not listed
Description
A memory-safety flaw in the key-management request-building component of the library can lead to an out-of-bounds write on the heap. A fixed-size output buffer is used under an assumption about cryptographic key size that is never validated, so when the library is embedded by a caller that supplies its own cryptographic callback implementation, data larger than the buffer can be written past its end. Exploitation requires the ability to control the embedding application's in-process key-management provider configuration, a high-privilege position. The demonstrated impact is memory corruption resulting in abnormal termination of the client process.
Affected Products
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CVE record
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NVD configurations
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Red Hat packages
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OpenCVE enrichment
No data
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| MongoDB | Libmongocrypt Driver | unaffected |
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No data available yet.
Remediation
Tracking
Advisories
Metrics
Attack Vector Local
Attack Complexity High
Privileges Required High
Attack Requirements Present
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact Low
Vulnerable System Availability Impact High
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
Attack Vector Local
Attack Complexity High
Privileges Required High
Scope Unchanged
Confidentiality Impact None
Integrity Impact Low
Availability Impact High
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.100% probability within 30 days)
Key SSVC decision points have not yet been added.
References
History
Nov 13, 2026 12:00 AM
Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A memory-safety flaw in the key-management request-building component of the library can lead to an out-of-bounds write on the heap. A fixed-size output buffer is used under an assumption about cryptographic key size that is never validated, so when the library is embedded by a caller that supplies its own cryptographic callback implementation, data larger than the buffer can be written past its end. Exploitation requires the ability to control the embedding application's in-process key-management provider configuration, a high-privilege position. The demonstrated impact is memory corruption resulting in abnormal termination of the client process. | |
| Title | Heap overflow via oversized RSA signature in GCP KMS signing callback | |
| Weaknesses | CWE-787 | |
| References |
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| Metrics |
cvssV3_1
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Subscriptions
No data.
Weaknesses
