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Fencer Vulns
critical 9.8

CVE-2018-6339 json

When receiving calls using WhatsApp on Android, a stack allocation failed to properly account for the amount of data being passed in.

published 2019-06-14 7 y ago modified 2026-06-17 4 mo ago also EUVD-2018-18099

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

When receiving calls using WhatsApp on Android, a stack allocation failed to properly account for the amount of data being passed in. An off-by-one error meant that data was written beyond the allocated space on the stack. This issue affects WhatsApp for Android starting in version 2.18.180 and was fixed in version 2.18.295. It also affects WhatsApp Business for Android starting in version v2.18.103 and was fixed in version v2.18.150.

Patch / fix

  • whatsapp whatsapp 2.18.295
  • whatsapp whatsapp_business 2.18.150

Exploit prediction

1.54% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Facebook WhatsApp for Android
  • Facebook WhatsApp Business for Android

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

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.