# 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.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Sep 2026
- **Updated:** 15 Sep 2026
- **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

## 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 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-80489?


## How do I fix CVE-2026-80489?

Apply the vendor's patch.

## Is CVE-2026-80489 being exploited?

There is no known exploitation of CVE-2026-80489 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80489 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-80489 in the wild and no public exploit code.

Affected product: The GNU C Library glibc. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80489/ (Markdown: https://insights.sbomify.com/CVE-2026-80489/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80489
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80489
- OSV: https://osv.dev/vulnerability/CVE-2026-80489

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-80489/
Summaries are generated and may contain mistakes; the official description above is the record.