CVE-2026-18536
CVE-2026-18536 is a high-severity vulnerability in Rrwo Data with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-319.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 0% (6th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-319
- Affected product: Rrwo Data
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-18536?
- 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.
- How severe is CVE-2026-18536?
- CVE-2026-18536 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2026-18536 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-18536?
- CVE-2026-18536 affects Rrwo Data. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-18536?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-18536 published?
- CVE-2026-18536 was published on 2026-08-01 and last updated on 2026-08-07.
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
Affected products (1)
- cpe:2.3:a:rrwo:data\:\:entropy:*:*:*:*:*:perl:*:*
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