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Fencer Vulns
high 7.8

CVE-2018-20819 json

io/ZlibCompression.cc in the decompression component in Dropbox Lepton 1.2.1 allows attackers to cause a denial of service (heap-based buff…

published 2019-04-23 7 y ago modified 2026-06-17 4 mo ago also EUVD-2018-13361

cvss
7.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 62%
public exploits
0
none known

Summary

io/ZlibCompression.cc in the decompression component in Dropbox Lepton 1.2.1 allows attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact by crafting a jpg image file. The root cause is a missing check of header payloads that may be (incorrectly) larger than the maximum file size.

Patch / fix

Exploit prediction

0.98% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/dropbox/lepton/issues/112 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 7.8 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.