# CVE-2026-73638: Imager versions from 0.45_02 before 1.035 for Perl read outside the EXIF block via unchecked start offsets in tiff_load_ifd.

> Attackers can read memory outside EXIF blocks or crash applications using the Imager Perl library by supplying crafted TIFF images with unchecked offsets.

- **Severity:** Medium 6.2 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-73638, GHSA-j47j-8w8p-3mmc, UBUNTU-CVE-2026-73638

## What is CVE-2026-73638?

CVE-2026-73638 is a medium-severity memory corruption vulnerability, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Imager versions from 0.45_02 before 1.035 for Perl read outside the EXIF block via unchecked start offsets in tiff_load_ifd.

tiff_load_ifd() validates an IFD entry's data by checking that `entry->offset + entry->size` stays within the EXIF block, and never checks the start offset itself. Where that sum is not the real end of the data, the check passes with the entry starting outside the block.

Through 1.032 `entry->offset` is a plain int, so on the usual two's-complement implementations an offset with the high bit set converts to negative and the sum can land back inside the block. From 1.033 the field is a size_t and the addition wraps only where size_t is 32 bits. The IFD's own start offset is checked the same way and wraps where unsigned long is 32 bits, which includes 64-bit Windows.

Any caller of Imager->read() on an attacker-supplied image may receive EXIF tags holding bytes from outside the block, or crash the process.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-73638?


## How do I fix CVE-2026-73638?

Upgrade to a fixed version.

## Is CVE-2026-73638 being exploited?

There is no known exploitation of CVE-2026-73638 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73638 and fix it if it is affected.

What it is: CVE-2026-73638 is a medium-severity memory corruption vulnerability, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-73638 in the wild and no public exploit code.

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-2026-73638/ (Markdown: https://insights.sbomify.com/CVE-2026-73638/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73638
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73638
- OSV: https://osv.dev/vulnerability/CVE-2026-73638

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73638/
Summaries are generated and may contain mistakes; the official description above is the record.