Attacker-controlled randomness via unauthenticated HTTP responses
Published Aug 1, 2026 · Updated Aug 1, 2026
Cleartext entropy retrieval in Data::Entropy before 0.010 allows man-in-the-middle attackers to control application random bytes. RandomOrg and RandomnumbersInfo use HTTP::Lite to feed plain-HTTP response bodies directly into the entropy buffer, while RandomOrg accepts any non-empty byte string as valid. Exposure requires an application to opt into either remote source through with_entropy_source; the default local source is unaffected, but reached calls return attacker-chosen randomness.
Summary
What happened
Cleartext entropy retrieval in Data::Entropy before 0.010 allows man-in-the-middle attackers to control application random bytes. RandomOrg and RandomnumbersInfo use HTTP::Lite to feed plain-HTTP response bodies directly into the entropy buffer, while RandomOrg accepts any non-empty byte string as valid. Exposure requires an application to opt into either remote source through with_entropy_source; the default local source is unaffected, but reached calls return attacker-chosen randomness.
The record
- CVE
- CVE-2026-18536
- Published
- Aug 1, 2026
- Updated
- Aug 1, 2026
- Vendor
- Robert Rothenberg
- Product
- Data::Entropy
- Classifications
- CWE-319, CWE-353, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 1, 2026CVE publishedPublication date reported by the CVE source.
- Aug 1, 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 <0.010
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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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