Is CVE-2017-17821 in the CISA KEV catalog?

No. CVE-2017-17821 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2017-17821?

CVE-2017-17821 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2017-17821?

CVE-2017-17821 has an EPSS score of 1.37% (69th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2017-17821?

Upgrade webkit2gtk on debian 11 to 2.22.0-2 or later.

CVE & CISA-KEV Catalog

CVE-2017-17821

CRITICAL

9.8

CVSS v3

NVD

Description

WTF/wtf/FastBitVector.h in WebKit, as distributed in Safari Technology Preview Release 46, allows remote attackers to cause a denial of service (buffer overflow) or possibly have unspecified other impact because it calls the FastBitVectorWordOwner::resizeSlow function (in WTF/wtf/FastBitVector.cpp) for a purpose other than initializing a bitvector size, and resizeSlow mishandles cases where the old array length is greater than the new array length.

CWE-119Buffer Overflow

How to fix

Remediation Available

webkit2gtkDebian

Fixed in:2.22.0-2CVE-2017-17821

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

1.37%probability of exploitation in 30 days

69thpercentile

Moderate risk: more likely to be exploited than 69% of all known CVEs.

References

Third-Party Advisory1

github.com

Other references1

bugs.webkit.org

Related Vulnerabilities

Other CWE-119 (Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-4966	Critical	9.4	100%	KEV + Ransom	Fix
CVE-2017-11882	High	7.8	100%	KEV + Ransom	-
CVE-2020-0796	Critical	10.0	100%	KEV + Ransom	-
CVE-2008-4250	Critical	9.8	99%	KEV	-
CVE-2017-15944	Critical	9.8	98%	KEV	Fix
CVE-2015-0014	High	10.0	97%	-	-

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-13.