What’s Vulnerable › Vulnerabilities

CVE-2026-18536: Data::Entropy versions before 0.010 for Perl read remote entropy sources over plain HTTP

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-01 · updated 2026-10-23
• Weakness: CWE-319

Description

Data::Entropy versions before 0.010 for Perl read remote entropy sources over plain HTTP. The Data::Entropy::RawSource::RandomOrg and Data::Entropy::RawSource::RandomnumbersInfo remote sources are accessed over plain HTTP. The Data::Entropy::RawSource::RandomOrg integrity check trivially matches any non-empty byte string. Any on-path attacker, such as open WiFi, a compromised ISP, captive portal, or a hostile egress proxy substitutes the response and thereby chooses the bytes returned by rand_bits and rand_int for every application that selected one of these sources via with_entropy_source. The _checkbuf method response is equally attacker-controlled, so the retry/sleep behaviour is steerable too.

Affected products

• RRWO Data::Entropy: before 0.010 — fixed in 0.010

How to fix

Upgrade to a fixed version: RRWO Data::Entropy 0.010. Check the vendor advisory for mitigations.

References

• https://github.com/robrwo/Data-Entropy/security/advisories/GHSA-845w-rcqw-jwvv
• https://metacpan.org/release/RRWO/Data-Entropy-0.008/view/lib/Data/Entropy.pm#STATUS
• https://metacpan.org/release/RRWO/Data-Entropy-0.010/changes
• https://security.metacpan.org/docs/guides/random-data-for-security.html
• http://www.openwall.com/lists/oss-security/2026/08/01/8

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