CVE-2026-40339

Heap disclosure via unchecked Sony FormFlag read

Published Apr 17, 2026 · Updated Apr 17, 2026

Out-of-bounds read in gPhoto libgphoto2 2.5.33 and earlier allows attackers to disclose heap data via a crafted Sony descriptor. The ptp_unpack_Sony_DPD() parser reads the FormFlag byte from a truncated Device Property Descriptor without first checking that the offset remains within dpdlen. A malicious USB device or rogue PTP/IP server must supply the descriptor during property enumeration, exposing one adjacent heap byte per enumeration.

CVSS severity5.2
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in gPhoto libgphoto2 2.5.33 and earlier allows attackers to disclose heap data via a crafted Sony descriptor. The ptp_unpack_Sony_DPD() parser reads the FormFlag byte from a truncated Device Property Descriptor without first checking that the offset remains within dpdlen. A malicious USB device or rogue PTP/IP server must supply the descriptor during property enumeration, exposing one adjacent heap byte per enumeration.

The record

CVE
CVE-2026-40339
Published
Apr 17, 2026
Updated
Apr 17, 2026
Vendor
gPhoto
Product
libgphoto2
Classifications
CWE-125, T1203
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 2.5.33

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

gPhoto · libgphoto2version=<= 2.5.33

Published CVSS scores

5.2GitHub, Inc.CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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