NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
🐹
🐹 Go
Not in CISA KEV
MEDIUM severity

CVE-2019-11840 — x/crypto

MEDIUM

CVE-2019-11840 is a medium-severity (CVSS 5.9) Insufficient Random Values vulnerability in golang.org/x/crypto. A fix is available for golang.org/x/crypto — see the affected versions and patch details below.

golang.org/x/crypto/salsa20/salsa uses insufficiently random values

Also known asGHSA-r5c5-pr8j-pfp7GO-2022-0209
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 29, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
3.5%probability of exploitation in next 30 days
Lower Risk-0.01%
Lower risk than most CVEs89th percentile — riskier than 89% of all scored CVEsHighest risk
1.59%2.38%3.17%3.96%2.7%3.5%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐹golang.org/x/crypto

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

An issue was discovered in supplementary Go cryptography libraries, aka golang-googlecode-go-crypto, before 2019-03-20. A flaw was found in the amd64 implementation of golang.org/x/crypto/salsa20 and golang.org/x/crypto/salsa20/salsa. If more than 256 GiB of keystream is generated, or if the counter otherwise grows greater than 32 bits, the amd64 implementation will first generate incorrect output, and then cycle back to previously generated keystream. Repeated keystream bytes can lead to loss of confidentiality in encryption applications, or to predictability in CSPRNG applications.

Specific Go Packages Affected

golang.org/x/crypto/salsa20/salsa

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogolang.org/x/cryptoall versions0.0.0-20190320223903-b7391e95e576go get golang.org/x/crypto@v0.0.0-20190320223903-b7391e95e576

Affected Products

2 products · 4 configurations
OS
debian linuxdebian
3 versions
8.09.010.0
Application
cryptogolang
all

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for golang.org/x/crypto, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update golang.org/x/crypto to 0.0.0-20190320223903-b7391e95e576 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-11840 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate
ProductFixed inAdvisory
Red Hat OpenShift Container Platform 3.11atomic-enterprise-service-catalog-1:3.11.374-1.git.1675.738abcc.el7RHSA-2021:0079
Red Hat OpenShift Container Platform 4.3openshift4/ose-hyperkube:v4.3.0-202001211731RHBA-2020:0062
Red Hat OpenShift Container Platform 4.3openshift-0:4.3.0-202001131753.git.0.0aee6a8.el7RHBA-2020:0063

Frequently Asked Questions

An issue was discovered in supplementary Go cryptography libraries, aka golang-googlecode-go-crypto, before 2019-03-20. A flaw was found in the amd64 implementation of golang.org/x/crypto/salsa20 and golang.org/x/crypto/salsa20/salsa. If more than 256 GiB of keystream is generated, or if the counter otherwise grows greater than 32 bits, the amd64 implementation will first generate incorrect output, and then cycle back to previously generated keystream. Repeated keystream bytes can lead to loss of confidentiality in encryption applications, or to predictability in CSPRNG applications. ### Spec
O3 Security · Impact-Aware SCA

Is CVE-2019-11840 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2019-11840: x/crypto — Fix Available