# CVE-2026-4046: iconv crash due to assertion failure with untrusted input > Attackers can crash applications using glibc by sending specific IBM1390 or IBM1399 character set inputs, causing an assertion failure. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/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:** 30 Mar 2026 - **Updated:** 15 Oct 2026 - **Also known as:** ALSA-2026:20587, ALSA-2026:20594, AZL-81273, BELL-CVE-2026-4046, CLSA-2026-1779733763, CLSA-2026-1780135072, CLSA-2026-1780323824, CLSA-2026-1780561907, CLSA-2026-1783697985, DEBIAN-CVE-2026-4046, ECHO-511d-493a-869e, GHSA-g7c4-wv7q-gcc6, MINI-6j3w-v9vw-6jj2, MINI-v3gc-mm7m-6225, MINI-vv9p-q45w-3qm8, OESA-2026-2031, OESA-2026-2032, OESA-2026-2033, OESA-2026-2034, OESA-2026-2035, RHSA-2026:20587, RHSA-2026:20594, RLSA-2026:20587, RLSA-2026:20594, SUSE-SU-2026:1498-1, SUSE-SU-2026:1501-1, SUSE-SU-2026:1662-1, SUSE-SU-2026:21317-1, SUSE-SU-2026:21395-1, SUSE-SU-2026:21424-1, SUSE-SU-2026:2465-1, UBUNTU-CVE-2026-4046, openSUSE-SU-2026:10722-1 ## What is CVE-2026-4046? CVE-2026-4046 is a high-severity denial of service vulnerability in Gnu Glibc, published on 30 Mar 2026. 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 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. Weakness: CWE-617 (Reachable Assertion) ## Which versions are affected by CVE-2026-4046? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `glibc` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-all-langpacks` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-benchtests` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-common` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-devel` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-doc` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-gconv-extra` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-aa` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-af` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-agr` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ak` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-am` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-an` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-anp` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ar` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-as` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ast` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ayc` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-az` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-be` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bem` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ber` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bg` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bhb` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bho` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bi` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bn` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bo` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-br` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-brx` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-bs` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-byn` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ca` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ce` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-chr` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-ckb` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-cmn` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-crh` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-cs` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | | `glibc-langpack-csb` | AlmaLinux:10 | All versions | 2.39-124.el10_2.alma.1 | Products: Gnu Glibc. ## How do I fix CVE-2026-4046? Change a configuration setting. ## Is CVE-2026-4046 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4046 exists. ## Other vulnerabilities in Gnu Glibc - [CVE-2026-5450](https://insights.sbomify.com/CVE-2026-5450/): scanf %mc off-by-one heap buffer overflow (critical 9.8) - [CVE-2023-25139](https://insights.sbomify.com/CVE-2023-25139/): Memory corruption in n/a (critical 9.8) - [CVE-1999-0199](https://insights.sbomify.com/CVE-1999-0199/): Other in n/a (critical 9.8) - [CVE-2019-1010022](https://insights.sbomify.com/CVE-2019-1010022/): Security feature bypass in glibc (critical 9.8) - [CVE-2005-3590](https://insights.sbomify.com/CVE-2005-3590/): Memory corruption in n/a (critical 9.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-4046 and fix it if it is affected. What it is: CVE-2026-4046 is a high-severity denial of service vulnerability in Gnu Glibc, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4046 exists. Affected product: Gnu 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-2026-4046/ (Markdown: https://insights.sbomify.com/CVE-2026-4046/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4046 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4046 - OSV: https://osv.dev/vulnerability/CVE-2026-4046 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-4046/ Summaries are generated and may contain mistakes; the official description above is the record.