# CVE-2026-40339: libgphoto2 has OOB read in ptp_unpack_Sony_DPD() FormFlag parsing in ptp-pack.c

> An out-of-bounds read in libgphoto2 allows attackers to cause denial of service or disclose memory contents via crafted Sony camera data.

- **Severity:** Medium 5.2 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L`)
- **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 Apr 2026
- **Updated:** 20 Apr 2026
- **Also known as:** AZL-83024, DEBIAN-CVE-2026-40339, GHSA-42cm-m9hc-r7q8, UBUNTU-CVE-2026-40339

## What is CVE-2026-40339?

CVE-2026-40339 is a medium-severity memory corruption vulnerability in libgphoto2, published on 17 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

libgphoto2 is a camera access and control library. Versions up to and including 2.5.33 have an out-of-bounds read in `ptp_unpack_Sony_DPD()` in `camlibs/ptp2/ptp-pack.c` (line 842). The function reads the FormFlag byte via `dtoh8o(data, *poffset)` without a prior bounds check. The standard `ptp_unpack_DPD()` at lines 686–687 correctly validates `*offset + sizeof(uint8_t) > dpdlen` before this same read, but the Sony variant omits this check entirely. Commit 09f8a940b1e418b5693f5c11e3016a1ad2cea62d fixes the issue.

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

## Which versions are affected by CVE-2026-40339?


## How do I fix CVE-2026-40339?

Apply the vendor's patch.

## Is CVE-2026-40339 being exploited?

There is no known exploitation of CVE-2026-40339 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40339 and fix it if it is affected.

What it is: CVE-2026-40339 is a medium-severity memory corruption vulnerability in libgphoto2, published on 17 Apr 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-2026-40339 in the wild and no public exploit code.

Affected product: libgphoto2. 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-2026-40339/ (Markdown: https://insights.sbomify.com/CVE-2026-40339/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40339
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40339
- OSV: https://osv.dev/vulnerability/CVE-2026-40339

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40339/
Summaries are generated and may contain mistakes; the official description above is the record.