CVE-2019-11840

An issue was discovered in the supplementary Go cryptography library, golang.org/x/crypto, before v0.0.0-20190320223903-b7391e95e576. A flaw was found in the amd64 implementation of the golang.org/x/crypto/salsa20 and golang.org/x/crypto/salsa20/salsa packages. 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.

Published: 2019-05-09 Last update: 2026-05-18 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-11840 is rated Moderate Risk (55.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.62%). EPSS rose +1.48% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-11840

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.14% 3.62% +1.48%
2 2026-05-26 1.79% 2.14% +0.36%
3 2026-05-22 — 1.79% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-11840

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2019-11840

GitHub Security Advisory for CVE-2019-11840

GHSA-r5c5-pr8j-pfp7 · Severity: medium · Ecosystem: go — golang.org/x/crypto/salsa20/salsa uses insufficiently random values

OS Trackers for CVE-2019-11840

vendor priority summary link
debian not yet assigned CVE-2019-11840 not yet assigned priority: Debian including 1 source packages (golang-go.crypto), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-11840
redhat medium — https://access.redhat.com/security/cve/CVE-2019-11840
ubuntu medium CVE-2019-11840 medium priority: Ubuntu including 3 source packages (golang-go.crypto, lxd, snapd), 49 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 22, ignored 20, needed 4, DNE 3. https://ubuntu.com/security/CVE-2019-11840

Affected software / configurations for CVE-2019-11840

Vendor Product Version Raw CPE
golang crypto — cpe:2.3:a:golang:crypto:-:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2019-11840

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1691529 Issue Tracking Vendor Advisory
https://github.com/golang/go/issues/30965 Third Party Advisory
https://go.googlesource.com/crypto/+/b7391e95e576cacdcdd422573063bc057239113d Mailing List Patch Third Party Advisory
https://groups.google.com/forum/#%21msg/golang-announce/tjyNcJxb2vQ/n0NRBziSCAAJ Permissions Required
https://lists.debian.org/debian-lts-announce/2019/06/msg00029.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00014.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/11/msg00016.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/11/msg00030.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/01/msg00015.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/06/msg00017.html Third Party Advisory
https://pkg.go.dev/vuln/GO-2022-0209 Third Party Advisory
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