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PatchSiren cyber security CVE debrief

CVE-2016-6238 Lepton Project CVE debrief

CVE-2016-6238 is a denial-of-service issue in Dropbox Lepton 1.0. According to NVD, the write_ujpg function in lepton/jpgcoder.cc can perform an out-of-bounds read when processing a crafted JPEG file. The issue is rated CVSS 5.5 (MEDIUM) and maps to CWE-125. For defenders, the main concern is untrusted image input reaching Lepton-based processing paths.

Vendor
Lepton Project
Product
Lepton
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-02
Original CVE updated
2026-05-13
Advisory published
2017-02-02
Advisory updated
2026-05-13

Who should care

Teams that use Dropbox Lepton 1.0 to process JPEG files, especially services or tools that accept untrusted images. Security and platform teams should care if Lepton is embedded in ingestion, conversion, backup, or media-processing workflows.

Technical summary

NVD describes the flaw as an out-of-bounds read in write_ujpg within lepton/jpgcoder.cc in Dropbox Lepton 1.0. The vulnerable condition can be triggered by a crafted JPEG file and is classified as CWE-125. The CVSS v3.0 vector is AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H, indicating a local impact path with user interaction required and high availability impact.

Defensive priority

Medium

Recommended defensive actions

  • Identify whether Dropbox Lepton 1.0 is deployed in your environment or bundled by another product.
  • Restrict or validate JPEG inputs before they reach Lepton processing components.
  • Upgrade or replace affected Lepton 1.0 deployments with a version not listed as vulnerable by the vendor or downstream package maintainer.
  • Monitor for crashes or service interruptions in image-processing workflows that handle untrusted files.
  • Review any automated file-conversion pipelines to ensure malformed media cannot interrupt availability.

Evidence notes

The NVD record identifies the affected CPE as lepton_project:lepton:1.0 and lists CWE-125. The CVSS v3.0 vector is AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H. References in the CVE data point to an oss-security mailing list post and a GitHub issue tracker entry, both tagged as patch/third-party advisory sources. The CVE was published on 2017-02-02 and later modified on 2026-05-13; those dates are used only as disclosure metadata.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-6238 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-6238

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-6238 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-6238

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.