# CVE-2026-18536

## Summary

- **CVE ID:** CVE-2026-18536
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
- **CWE:** CWE-319, CWE-353
- **Published:** Aug 1, 2026
- **Last Modified:** Aug 3, 2026

## 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 (0)

## References

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

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.16%
- **EPSS Percentile:** 5.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._