Process crash via prime-one validation bypass
Published Jan 8, 2026 · Updated Jan 8, 2026
Improper exception handling in RustCrypto rsa before 0.9.10 allows attackers to crash consuming processes via private keys with prime 1. The src/key.rs validation in RsaPrivateKey::from_components rejects primes below 1 but accepts 1, so later arithmetic divides by zero and panics. Reachability requires a consuming application to pass attacker-controlled RSA private-key components into the constructor; the library exposes no network service by itself.
Summary
What happened
Improper exception handling in RustCrypto rsa before 0.9.10 allows attackers to crash consuming processes via private keys with prime 1. The src/key.rs validation in RsaPrivateKey::from_components rejects primes below 1 but accepts 1, so later arithmetic divides by zero and panics. Reachability requires a consuming application to pass attacker-controlled RSA private-key components into the constructor; the library exposes no network service by itself.
The record
- CVE
- CVE-2026-21895
- Published
- Jan 8, 2026
- Updated
- Jan 8, 2026
- Vendor
- RustCrypto
- Product
- rsa
- Classifications
- CWE-703, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 8, 2026CVE publishedPublication date reported by the CVE source.
- Jan 8, 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?
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- Affected versionversion=< 0.9.10
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What is affected?
Published CVSS scores
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Attacks
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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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