# CVE-2026-18495: Libtiff: libtiff: heap-buffer overflow via numeric truncation in the jpeg raw passthrough

> An attacker can trigger memory corruption and potential code execution by providing a crafted BigTIFF file to the tiff2pdf utility due to integer truncation.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 7 Oct 2026
- **Also known as:** AZL-101736, BELL-CVE-2026-18495, DEBIAN-CVE-2026-18495, ECHO-43b5-a32b-c56f, GHSA-6x88-8xw5-p2gw, OESA-2026-4063, SUSE-SU-2026:4252-1, SUSE-SU-2026:4845-1, UBUNTU-CVE-2026-18495

## What is CVE-2026-18495?

CVE-2026-18495 is a medium-severity vulnerability in Red Hat Ceph Storage 4, published on 11 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A flaw was found in libtiff. A heap-buffer overflow vulnerability exists in the `tiff2pdf` utility due to an integer truncation error when processing crafted BigTIFF files. An attacker can provide a specially crafted BigTIFF file, causing a 64-bit `StripByteCounts` value to be truncated to a 32-bit integer. This leads to an undersized memory allocation and a subsequent out-of-bounds memory copy, resulting in a crash and severe memory corruption.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-18495?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `tiff` | SUSE:Linux Enterprise Micro 5.3 | All versions | 4.0.9-150000.45.72.1 |
| `tiff` | SUSE:Linux Enterprise Micro 5.4 | All versions | 4.0.9-150000.45.72.1 |
| `tiff` | SUSE:Linux Enterprise Micro 5.5 | All versions | 4.0.9-150000.45.72.1 |
| `tiff` | SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 4.0.9-150000.45.72.1 |
| `tiff` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 4.0.9-44.118.1 |

## How do I fix CVE-2026-18495?

Apply the vendor's patch.

## Is CVE-2026-18495 being exploited?

There is no known exploitation of CVE-2026-18495 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18495 and fix it if it is affected.

What it is: CVE-2026-18495 is a medium-severity vulnerability in Red Hat Ceph Storage 4, published on 11 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-18495 in the wild and no public exploit code.

Affected product: Red Hat Ceph Storage 4. 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-2026-18495/ (Markdown: https://insights.sbomify.com/CVE-2026-18495/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18495
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18495
- OSV: https://osv.dev/vulnerability/CVE-2026-18495

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18495/
Summaries are generated and may contain mistakes; the official description above is the record.