How severe is CVE-2018-20655?

CVE-2018-20655 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-20655 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20655?

CVE-2018-20655 primarily affects Whatsapp. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-20655?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2018-20655 published?

CVE-2018-20655 was published on 2019-06-14 and last updated on 2026-06-17.

CVE-2018-20655

CVE-2018-20655 is a critical-severity vulnerability in Whatsapp with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Whatsapp
Published: 2019-06-14
Last modified: 2026-06-17

Description

When receiving calls using WhatsApp for iOS, a missing size check when parsing a sender-provided packet allowed for a stack-based overflow. This issue affects WhatsApp for iOS prior to v2.18.90.24 and WhatsApp Business for iOS prior to v2.18.90.24.

Frequently asked questions

What is CVE-2018-20655?: When receiving calls using WhatsApp for iOS, a missing size check when parsing a sender-provided packet allowed for a stack-based overflow. This issue affects WhatsApp for iOS prior to v2.18.90.24 and WhatsApp Business for iOS prior to v2.18.90.24.
How severe is CVE-2018-20655?: CVE-2018-20655 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-20655 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20655?: CVE-2018-20655 primarily affects Whatsapp. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-20655?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-20655 published?: CVE-2018-20655 was published on 2019-06-14 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:iphone_os:*:*
cpe:2.3:a:whatsapp:whatsapp_business:*:*:*:*:*:iphone_os:*:*

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