CVE-2017-17821

critical
Published 2017-12-21 · Modified 2026-05-13
CVSS v3
9.8
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2
7.5
VIR risk
9.8

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.

Predictions

Exploit likelihood
97%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2017-17821

OS impact

OSVersionStatusFixed in
debian debianbookwormfixed2.22.0-2
debian debianbullseyefixed2.22.0-2
debian debianforkyfixed2.22.0-2
debian debiansidfixed2.22.0-2
debian debiantrixiefixed2.22.0-2

Application impact

VendorProductVersionsFixed
applesafari46

References

CWEs

CWE-119

Verify integrity in audit chain (admin only). AS-IS.