CVE-2020-21913: International Components for Unicode (ICU-20850) v66.1 was discovered to contain a use after free bug in the p

Q: How do I fix CVE-2020-21913?

international components for unicode: upgrade to 66.1; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2020-21913 being exploited?

CVE-2020-21913 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-2020-21913 affect?

CVE-2020-21913 affects international components for unicode, debian linux. Severity is medium (CVSS 5.5). International Components for Unicode (ICU-20850) v66.1 was discovered to contain a use after free bug in the pkg_createWithAssemblyCode function in the file tools/pkgdata/pkgdata.cpp.

Q: How urgent is CVE-2020-21913?

Priority 46/100. Public exploit reference; On your watchlist

This month

MEDIUM 5.5WATCHLISTUPGRADEMITIGATE

CVE-2020-21913 is a medium-severity flaw (CVSS 5.5) affecting international components for unicode, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

International Components for Unicode (ICU-20850) v66.1 was discovered to contain a use after free bug in the pkg_createWithAssemblyCode function in the file tools/pkgdata/pkgdata.cpp.

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.2% (top 32%)
CISA exploited list	No
Weakness	CWE-416
Published	2021-09-20
Last modified	2026-10-14

Publisher (CNA): MITRE · Vendor: debian · unicode

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-09-20 14:15 UTCPublished CVE record published
2026-10-14 10:17 UTCUpdated Record last modified

unicode international components for unicode UPGRADE

Affected: < 66.1

Fixed in: 66.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy international-components-for-unicode || rpm -q international-components-for-unicode || international-components-for-unicode --version

2. UPGRADE to 66.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade international-components-for-unicode

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade international-components-for-unicode

Note

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

debian debian linux MITIGATE

Affected: 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2020-21913?

international components for unicode: upgrade to 66.1; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-21913 being exploited?

CVE-2020-21913 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-2020-21913 affect?

CVE-2020-21913 affects international components for unicode, debian linux. Severity is medium (CVSS 5.5). International Components for Unicode (ICU-20850) v66.1 was discovered to contain a use after free bug in the pkg_createWithAssemblyCode function in the file tools/pkgdata/pkgdata.cpp.

How urgent is CVE-2020-21913?

Priority 46/100. Public exploit reference; On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

CVE-2025-5222 HIGH 7.0 UPGRADE A stack buffer overflow was found in Internationl components for unicode (ICU )
CVE-2020-10531 HIGH 8.8 UPGRADE MITIGATE An issue was discovered in International Components for Unicode (ICU) for C/C++ through 66.1
CVE-2018-18928 CRITICAL 9.8 DOWNGRADE International Components for Unicode (ICU) for C/C++ 63.1 has an integer overflow in number::impl::DecimalQuan
CVE-2017-15422 MEDIUM 6.5 UPGRADE UPGRADE Integer overflow in international date handling in International Components for Unicode (ICU) for C/C++ before
CVE-2017-7868 HIGH 7.5 UPGRADE MITIGATE International Components for Unicode (ICU) for C/C++ before 2017-02-13 has an out-of-bounds write caused by a

References

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