CVE-2018-18928: International Components for Unicode (ICU) for C/C++ 63.1 has an integer overflow in number::impl::DecimalQuan

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2018-18928 is a critical-severity flaw (CVSS 9.8) affecting international components for unicode. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

International Components for Unicode (ICU) for C/C++ 63.1 has an integer overflow in number::impl::DecimalQuantity::toScientificString() in i18n/number_decimalquantity.cpp.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.9% (top 13%)
CISA exploited list	No
Weakness	CWE-190
Published	2018-11-04
Last modified	2026-10-14

Publisher (CNA): MITRE · Vendor: icu-project

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

Am I affected?

Timeline

2018-11-04 20:29 UTCPublished CVE record published
2026-10-14 07:16 UTCUpdated Record last modified

icu-project international components for unicode DOWNGRADE

Affected: 63.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 63.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 63.1 (Debian / Ubuntu)

apt-cache madison international-components-for-unicode sudo apt install international-components-for-unicode=<VERSION_BEFORE_63.1> sudo apt-mark hold international-components-for-unicode

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list international-components-for-unicode sudo dnf downgrade international-components-for-unicode-<VERSION_BEFORE_63.1> sudo dnf versionlock add international-components-for-unicode

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2018-18928?

international components for unicode: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-18928 being exploited?

CVE-2018-18928 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-2018-18928 affect?

CVE-2018-18928 affects international components for unicode. Severity is critical (CVSS 9.8). International Components for Unicode (ICU) for C/C++ 63.1 has an integer overflow in number::impl::DecimalQuantity::toScientificString() in i18n/number_decimalquantity.cpp.

How urgent is CVE-2018-18928?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-5222 HIGH 7.0 UPGRADE A stack buffer overflow was found in Internationl components for unicode (ICU )
CVE-2020-21913 MEDIUM 5.5 UPGRADE MITIGATE International Components for Unicode (ICU-20850) v66.1 was discovered to contain a use after free bug in the p
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-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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