CVE-2026-80489 EUC_JISX0213 decoding may hang on crafted input
An attacker can cause a denial of service by providing crafted EUC_JISX0213 input that triggers an infinite loop in the glibc iconv converter.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80489?
CVE-2026-80489 is a medium-severity denial of service vulnerability in The GNU C Library glibc, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Converting crafted EUC_JISX0213 input to UCS-4 or the internal wide character encoding, for example with iconv, in the GNU C Library version 2.3 to 2.44 may result in the converter making no progress, causing the calling application to hang.
Some EUC_JISX0213 sequences decode to two code points. If the output buffer has room for only the first one, the converter stores the second in the conversion state and returns E2BIG, but it never clears that pending character after emitting it on the next call. The converter then keeps emitting the pending character without consuming further input, so an application that retries the conversion loops forever. The input must be attacker controlled and the application must convert it with an output buffer small enough to split the two code points. Only the EUC_JISX0213 character set is affected, which is not commonly used. The related defect in SHIFT_JISX0213 converter is tracked separately as CVE-2026-77117.
Weakness: CWE-835
Which versions are affected by CVE-2026-80489?
How do I fix CVE-2026-80489?
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-2026-80489 being exploited?
There is no known exploitation of CVE-2026-80489 in the wild and no public exploit code.
Sources
Also known as AZL-100965, BELL-CVE-2026-80489, DEBIAN-CVE-2026-80489, ECHO-add6-7bb2-f327, GHSA-w45w-pf39-v4pp, UBUNTU-CVE-2026-80489.