CVE-2021-38561

golang.org/x/text/language in golang.org/x/text before 0.3.7 can panic with an out-of-bounds read during BCP 47 language tag parsing. Index calculation is mishandled. If parsing untrusted user input, this can be used as a vector for a denial-of-service attack.

Published: 2022-12-26 Last update: 2025-04-14 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-38561 is rated Low Risk (36.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.07%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2021-38561

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 2025-11-21 0.84% 0.07% -0.77%
2 2025-11-18 0.09% 0.84% +0.75%
3 2025-08-19 — 0.09% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38561

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2021-38561

GitHub Security Advisory for CVE-2021-38561

GHSA-ppp9-7jff-5vj2 · Severity: high · Ecosystem: go — golang.org/x/text/language Out-of-bounds Read vulnerability

OS Trackers for CVE-2021-38561

vendor priority summary link
alpine — CVE-2021-38561: 1 source package rows (git-lfs); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2021-38561
debian not yet assigned CVE-2021-38561 not yet assigned priority: Debian including 1 source packages (golang-golang-x-text), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-38561
redhat medium — https://access.redhat.com/security/cve/CVE-2021-38561
suse high CVE-2021-38561 severity important: SUSE including 11 source package names (cni, cni-1.1.2-2.1, …), 77 product×package rows across 35 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (35 product lines)): Known Not Affected 73, Fixed 4. https://www.suse.com/security/cve/CVE-2021-38561/
ubuntu medium CVE-2021-38561 medium priority: Ubuntu including 2 source packages (golang-golang-x-text, golang-x-text), 28 status rows across 14 suites (bionic, focal, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 13, released 10, ignored 2, needs-triage 2, needed 1. https://ubuntu.com/security/CVE-2021-38561

Affected software / configurations for CVE-2021-38561

Vendor Product Version Raw CPE
golang text < 0.3.7 cpe:2.3:a:golang:text:*:*:*:*:*:*:*:*

References for CVE-2021-38561

cvelogic Threat Intelligence