Service interruption via uncaught RSA exception
Published Sep 9, 2026 · Updated Sep 9, 2026
Improper input validation in OCaml mirage-crypto-pk before 2.3.0 allows remote authenticated users to interrupt services with small RSA values. The RSA encrypt and decrypt paths raise an undocumented Invalid_argument exception when the message integer is below 2, rather than the documented Insufficient_key error that callers handle. Applications that pass attacker-controlled signatures or ciphertext values of 0 or 1 into these paths can terminate an operation or service process when the exception is uncaught.
Summary
What happened
Improper input validation in OCaml mirage-crypto-pk before 2.3.0 allows remote authenticated users to interrupt services with small RSA values. The RSA encrypt and decrypt paths raise an undocumented Invalid_argument exception when the message integer is below 2, rather than the documented Insufficient_key error that callers handle. Applications that pass attacker-controlled signatures or ciphertext values of 0 or 1 into these paths can terminate an operation or service process when the exception is uncaught.
The record
- CVE
- CVE-2026-87735
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Vendor
- OCaml
- Product
- mirage-crypto-pk
- Classifications
- CWE-248, CWE-1284, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 9, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2.3.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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