Out-of-bounds Read in Gphoto Libgphoto2

CVE-2026-40339

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.2 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L.

EPSS exploit prediction

EPSS: 0.002 (11.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 11.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-40339: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40339?
CVE-2026-40339 is a medium-severity vulnerability in Gphoto Libgphoto2, classified under Out-of-bounds Read. CVSS score: 5.2/10. Published 2026-04-18.
How severe is CVE-2026-40339?
Medium severity. CVSS v3 base score is 5.2 out of 10.