CVE-2020-35926: An issue was discovered in the nanorand crate before 0.5.1 for Rust

Q: How do I fix CVE-2020-35926?

nanorand: upgrade to 0.5.1. Exact commands for each OS are on this page.

Q: Is CVE-2020-35926 being exploited?

CVE-2020-35926 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-35926 affect?

CVE-2020-35926 affects nanorand. Severity is critical (CVSS 9.8). An issue was discovered in the nanorand crate before 0.5.1 for Rust. It caused any random number generator (even ChaCha) to return all zeroes because integer truncation was mishandled.

Q: How urgent is CVE-2020-35926?

Priority 58/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2020-35926 is a critical-severity flaw (CVSS 9.8) affecting nanorand. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in the nanorand crate before 0.5.1 for Rust. It caused any random number generator (even ChaCha) to return all zeroes because integer truncation was mishandled.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.5% (top 25%)
CISA exploited list	No
Weakness	CWE-330, CWE-681
Published	2020-12-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: nanorand project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-12-31 09:15 UTCPublished CVE record published
2026-06-17 03:14 UTCUpdated Record last modified

nanorand project nanorand UPGRADE

Affected: < 0.5.1

Fixed in: 0.5.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy nanorand || rpm -q nanorand || nanorand --version

2. UPGRADE to 0.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade nanorand

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade nanorand

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-35926?

nanorand: upgrade to 0.5.1. Exact commands for each OS are on this page.

Is CVE-2020-35926 being exploited?

CVE-2020-35926 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-35926 affect?

CVE-2020-35926 affects nanorand. Severity is critical (CVSS 9.8). An issue was discovered in the nanorand crate before 0.5.1 for Rust. It caused any random number generator (even ChaCha) to return all zeroes because integer truncation was mishandled.

How urgent is CVE-2020-35926?

Priority 58/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-45705 CRITICAL 9.8 UPGRADE An issue was discovered in the nanorand crate before 0.6.1 for Rust

References

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