Undersized buffers via output length integer wraparound
Published Mar 8, 2026 · Updated Mar 8, 2026
Integer overflow in Crypt::NaCl::Sodium 2.002 and earlier allows attackers to create undersized buffers via extremely large inputs. The bin2hex, encrypt, aes256gcm_encrypt_afternm, and seal functions add or multiply input lengths without first checking against SIZE_MAX, so wrapped output sizes allocate too little memory. Exploitation requires lengths near SIZE_MAX; published sources do not establish whether the resulting overwrite causes a crash, code execution, or another consequence.
Summary
What happened
Integer overflow in Crypt::NaCl::Sodium 2.002 and earlier allows attackers to create undersized buffers via extremely large inputs. The bin2hex, encrypt, aes256gcm_encrypt_afternm, and seal functions add or multiply input lengths without first checking against SIZE_MAX, so wrapped output sizes allocate too little memory. Exploitation requires lengths near SIZE_MAX; published sources do not establish whether the resulting overwrite causes a crash, code execution, or another consequence.
The record
- CVE
- CVE-2026-30909
- Published
- Mar 8, 2026
- Updated
- Mar 8, 2026
- Vendor
- Timothy Legge
- Product
- Crypt::NaCl::Sodium
- Classifications
- CWE-190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 8, 2026CVE publishedPublication date reported by the CVE source.
- Mar 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 <=2.002
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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