CVE-2026-4046: The iconv() function in the GNU C Library versions 2.43 and earlier may crash due to an assertion failure when

Q: How do I fix CVE-2026-4046?

glibc: upgrade to newer than 2.43. Exact commands for each OS are on this page.

Q: Is CVE-2026-4046 being exploited?

CVE-2026-4046 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-2026-4046 affect?

CVE-2026-4046 affects glibc. Severity is high (CVSS 7.5). The iconv() function in the GNU C Library versions 2.43 and earlier may crash due to an assertion failure when converting inputs from the IBM1390 or IBM1399 character sets, which may be used to remotely crash an application. This vulnera

Q: How urgent is CVE-2026-4046?

Priority 44/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-4046 is a high-severity flaw (CVSS 7.5) affecting glibc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The iconv() function in the GNU C Library versions 2.43 and earlier may crash due to an assertion failure when converting inputs from the IBM1390 or IBM1399 character sets, which may be used to remotely crash an application. This vulnerability can be trivially mitigated by removing the IBM1390 and IBM1399 character sets from systems that do not need them.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-617
Published	2026-03-30
Last modified	2026-07-14

Publisher (CNA): GNU C Library · Vendor: gnu

Last updated 2026-07-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-30 18:16 UTCPublished CVE record published
2026-07-14 13:18 UTCUpdated Record last modified

gnu glibc UPGRADE

Affected: <= 2.43

Fixed in: newer than 2.43

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy glibc || rpm -q glibc || glibc --version

2. UPGRADE to newer than 2.43 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade glibc

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade glibc

Note

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

Advisories and coverage

Official advisories

AlmaLinux Errata: [ALSA-2026:20597] Moderate: glibc security update 2026-06-30

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-2026-4046?

glibc: upgrade to newer than 2.43. Exact commands for each OS are on this page.

Is CVE-2026-4046 being exploited?

CVE-2026-4046 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-2026-4046 affect?

CVE-2026-4046 affects glibc. Severity is high (CVSS 7.5). The iconv() function in the GNU C Library versions 2.43 and earlier may crash due to an assertion failure when converting inputs from the IBM1390 or IBM1399 character sets, which may be used to remotely crash an application. This vulnera

How urgent is CVE-2026-4046?

Priority 44/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

glibc vulnerabilities

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References

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