CVE-2021-3326 Denial of service in n/a

What is CVE-2021-3326?

CVE-2021-3326 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 27 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid input sequences in the ISO-2022-JP-3 encoding, fails an assertion in the code path and aborts the program, potentially resulting in a denial of service.

Weakness: CWE-617

Which versions are affected by CVE-2021-3326?

It affects 11 products.

Products include Debian Debian Linux, Fujitsu M10-1 Firmware, Fujitsu M10-4 Firmware, Fujitsu M10-4s Firmware, Fujitsu M12-1 Firmware, Fujitsu M12-2 Firmware and 5 more.

How do I fix CVE-2021-3326?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-3326 being exploited?

There is no known exploitation of CVE-2021-3326 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as CLSA-2026-1777481470, DEBIAN-CVE-2021-3326, GHSA-w279-vhxx-7qx8, OESA-2021-1045, UBUNTU-CVE-2021-3326.