# CVE-2026-26740: Memory corruption in n/a

> A remote attacker can cause a denial of service in applications using giflib by triggering a buffer overflow in the Graphic Control Extension handling.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:** 18 Mar 2026
- **Updated:** 23 Jul 2026
- **Also known as:** ALPINE-CVE-2026-26740, ALSA-2026:33501, ALSA-2026:33502, ALSA-2026:33503, BELL-CVE-2026-26740, CLEANSTART-2026-IJ74212, CLSA-2026-1779265764, CLSA-2026-1779290839, DEBIAN-CVE-2026-26740, ECHO-72ce-97fd-d225, GHSA-g43h-fmhp-fvff, JLSEC-2026-822, MGASA-2026-0295, OESA-2026-2685, OESA-2026-2706, OESA-2026-2707, OESA-2026-2708, OESA-2026-3054, RHSA-2026:33447, RHSA-2026:33450, RHSA-2026:33451, RHSA-2026:33452, RHSA-2026:33455, RHSA-2026:33456, RHSA-2026:33501, RHSA-2026:33502, RHSA-2026:33503, RHSA-2026:33509, RLSA-2026:33501, RLSA-2026:33502, RLSA-2026:33503, SUSE-SU-2026:22382-1, SUSE-SU-2026:2666-1, SUSE-SU-2026:2667-1, UBUNTU-CVE-2026-26740, openSUSE-SU-2026:11117-1, openSUSE-SU-2026:21076-1

## What is CVE-2026-26740?

CVE-2026-26740 is a high-severity memory corruption vulnerability in n/a, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Buffer Overflow vulnerability in giflib v.5.2.2 allows a remote attacker to cause a denial of service via the EGifGCBToExtension overwriting an existing Graphic Control Extension block without validating its allocated size.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-26740?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `giflib` | AlmaLinux:10 | All versions | 5.2.1-25.el10_2 |
| `giflib-devel` | AlmaLinux:10 | All versions | 5.2.1-25.el10_2 |
| `giflib` | AlmaLinux:8 | All versions | 5.1.4-5.el8_10 |
| `giflib-devel` | AlmaLinux:8 | All versions | 5.1.4-5.el8_10 |
| `giflib` | AlmaLinux:9 | All versions | 5.2.1-10.el9_8.2 |
| `giflib-devel` | AlmaLinux:9 | All versions | 5.2.1-10.el9_8.2 |
| `giflib` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.2.1-25.el10_2 |
| `giflib-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.2.1-25.el10_2 |
| `giflib-debugsource` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.2.1-25.el10_2 |
| `giflib-devel` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.2.1-25.el10_2 |
| `giflib-utils-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.2.1-25.el10_2 |
| `giflib` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.1.4-5.el8_10 |
| `giflib-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.1.4-5.el8_10 |
| `giflib-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.1.4-5.el8_10 |
| `giflib-utils-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.1.4-5.el8_10 |
| `giflib-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:5.1.4-5.el8_10 |
| `giflib-debugsource` | Red Hat:enterprise_linux:8::crb | All versions | 0:5.1.4-5.el8_10 |
| `giflib-devel` | Red Hat:enterprise_linux:8::crb | All versions | 0:5.1.4-5.el8_10 |
| `giflib-utils-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:5.1.4-5.el8_10 |
| `giflib` | Red Hat:enterprise_linux:9::appstream | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib-utils-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib-debugsource` | Red Hat:enterprise_linux:9::crb | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib-devel` | Red Hat:enterprise_linux:9::crb | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib-utils-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:5.2.1-10.el9_8.2 |
| `giflib` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.2.1-22.el10_0.2 |
| `giflib-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.2.1-22.el10_0.2 |
| `giflib-debugsource` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.2.1-22.el10_0.2 |
| `giflib-devel` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.2.1-22.el10_0.2 |
| `giflib-utils-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.2.1-22.el10_0.2 |
| `giflib` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:5.1.4-3.el8_4.2 |
| `giflib-debuginfo` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:5.1.4-3.el8_4.2 |
| `giflib-debugsource` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:5.1.4-3.el8_4.2 |
| `giflib-utils-debuginfo` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:5.1.4-3.el8_4.2 |
| `giflib` | Red Hat:rhel_aus:8.6::appstream | All versions | 0:5.1.4-3.el8_6.2 |
| `giflib-debuginfo` | Red Hat:rhel_aus:8.6::appstream | All versions | 0:5.1.4-3.el8_6.2 |
| `giflib-debugsource` | Red Hat:rhel_aus:8.6::appstream | All versions | 0:5.1.4-3.el8_6.2 |
| `giflib-utils-debuginfo` | Red Hat:rhel_aus:8.6::appstream | All versions | 0:5.1.4-3.el8_6.2 |

Products: Giflib Project Giflib.

## How do I fix CVE-2026-26740?

Upgrade to a fixed version.

## Is CVE-2026-26740 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-26740 exists.

## Other vulnerabilities in n/a

- [CVE-2016-3177](https://insights.sbomify.com/CVE-2016-3177/): Use after free in n/a (critical 9.8)
- [CVE-2021-40633](https://insights.sbomify.com/CVE-2021-40633/): Denial of service in n/a (high 8.8)
- [CVE-2018-11489](https://insights.sbomify.com/CVE-2018-11489/): Memory corruption in n/a (high 8.8)
- [CVE-2023-48161](https://insights.sbomify.com/CVE-2023-48161/): Memory corruption in n/a (high 7.1)
- [CVE-2024-45993](https://insights.sbomify.com/CVE-2024-45993/): Memory corruption in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26740 and fix it if it is affected.

What it is: CVE-2026-26740 is a high-severity memory corruption vulnerability in n/a, published on 18 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-2026-26740 exists.

Affected product: n/a. 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-2026-26740/ (Markdown: https://insights.sbomify.com/CVE-2026-26740/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26740
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26740
- OSV: https://osv.dev/vulnerability/CVE-2026-26740

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26740/
Summaries are generated and may contain mistakes; the official description above is the record.