Vulnerability · Published Aug 1, 2026 · Assigned by CPANSec
CVE-2026-18536Data::Entropy versions before 0.010 for Perl read remote entropy sources over plain HTTP
High 7.5
In plain English
A high-severity security flaw in Data::Entropy from RRWO. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libdata-entropy-perl | no fix listed | DEBIAN-CVE-2026-18536 |
| Debian:13 | libdata-entropy-perl | no fix listed | DEBIAN-CVE-2026-18536 |
| Debian:14 | libdata-entropy-perl | no fix listed | DEBIAN-CVE-2026-18536 |
| Ubuntu:22.04:LTS | libdata-entropy-perl | no fix listed | UBUNTU-CVE-2026-18536 |
| Ubuntu:24.04:LTS | libdata-entropy-perl | no fix listed | UBUNTU-CVE-2026-18536 |
| Ubuntu:26.04:LTS | libdata-entropy-perl | no fix listed | UBUNTU-CVE-2026-18536 |
| Ubuntu:26.10 | libdata-entropy-perl | no fix listed | UBUNTU-CVE-2026-18536 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| RRWO | Data::Entropy | 0 – before 0.010 |
Weakness: CWE-319, CWE-353 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/robrwo/Data-Entropy/security/advisories/GHSA-845w-rcqw-jwvv vendor-advisory
- https://metacpan.org/release/RRWO/Data-Entropy-0.010/changes release-notes
- https://metacpan.org/release/RRWO/Data-Entropy-0.008/view/lib/Data/Entropy.pm#STATUS
- https://security.metacpan.org/docs/guides/random-data-for-security.html technical-description
- http://www.openwall.com/lists/oss-security/2026/08/01/8