CVE-2021-30952
HighExploitedPublic exploitAn integer overflow was addressed with improved input validation.
Published Aug 24, 2021 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2021-30952, UBUNTU-CVE-2021-30952
Key Facts
Patch immediately- CVE-2021-30952 is a high-severity vulnerability (CVSS 8.8 v3.1) affecting Safari (Apple), Webkitgtk, Wpe Webkit (Wpewebkit) and 22 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 3, 2026. Public exploit code is available.
- EPSS estimates a 7.0% probability of exploitation in the next 30 days.
- Fixed versions are available, including Ipados 15.2, Iphone OS 15.2, macOS 12.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
8.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
7.0%
Higher than 94.0% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-30952 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 5, 2026 | Mar 26, 2026 | Not reported |
| Industry KEV feed | Mar 3, 2026 | Mar 26, 2026 | Not reported |
| CIRCL KEV | Mar 5, 2026 | Mar 26, 2026 | Not reported |
| ENISA EUVD | Mar 5, 2026 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected Products
376 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| SafariApple | See advisory | 15.2 |
| WebkitgtkWebkitgtk | See advisory | 2.34.4 |
| Wpe WebkitWpewebkit | See advisory | 2.34.4 |
| IpadosApple | See advisory | 15.2 |
| Iphone OSApple | See advisory | 15.2 |
Patched Releases
Ipados
15.2
Iphone OS
15.2
macOS
12.1, 15.2
Safari
15.2
Tvos
15.2
watchOS
8.3
iOS and iPadOS
15.2
libjavascriptcoregtk-4_0-18
2.34.5-2.85.3, 2.34.6-29.1, 2.34.6-3.97.1
libjavascriptcoregtk-4_0-18-32bit
2.34.6-29.1
libwebkit2gtk-4_0-37
2.34.5-2.85.3, 2.34.6-29.1, 2.34.6-3.97.1
libwebkit2gtk-4_0-37-32bit
2.34.6-29.1
libwebkit2gtk3-lang
2.34.5-2.85.3, 2.34.6-29.1, 2.34.6-3.97.1
typelib-1_0-JavaScriptCore-4_0
2.34.5-2.85.3, 2.34.6-29.1, 2.34.6-3.97.1
typelib-1_0-WebKit2-4_0
2.34.5-2.85.3, 2.34.6-29.1, 2.34.6-3.97.1
typelib-1_0-WebKit2WebExtension-4_0
2.34.5-2.85.3, 2.34.6-29.1, 2.34.6-3.97.1
webkit-jsc-4
2.34.6-29.1
webkit2gtk
2.34.4-0ubuntu0.20.04.1, 2.34.4-1, 2.34.4-1~deb10u1, 2.34.4-1~deb11u1, 2.34.4-r0
webkit2gtk-4_0-injected-bundles
2.34.5-2.85.3, 2.34.6-29.1, 2.34.6-3.97.1
webkit2gtk3
0:2.34.6-1.el8, 2.34.5-2.85.3, 2.34.6-1.el8, 2.34.6-29.1, 2.34.6-3.97.1
webkit2gtk3-devel
2.34.5-2.85.3, 2.34.6-1.el8, 2.34.6-29.1, 2.34.6-3.97.1
webkit2gtk3-jsc
2.34.6-1.el8
webkit2gtk3-jsc-devel
2.34.6-1.el8
webkit2gtk3-minibrowser
2.34.6-29.1
Webkitgtk
2.34.4
webkitgtk4
0:2.48.3-2.el7_9, 2.38.5-3.amzn2.0.1
Timeline
Publicly disclosed
Aug 24, 2021
Added to Industry KEV feed
Mar 3, 2026
Added to CISA KEV
Mar 5, 2026
Added to CIRCL KEV
Mar 5, 2026
Added to ENISA EUVD
Mar 5, 2026
Last updated
Aug 4, 2026
Weakness Type
- CWE-190 Integer Overflow or Wraparound
References
- advisoryRHSA-2022:1777
- advisoryRHSA-2025:10364
- advisoryhttps://bugzilla.suse.com/1195064
- advisoryhttps://bugzilla.suse.com/1195735
- advisoryhttps://bugzilla.suse.com/1196133
FAQ
Common Questions.
An integer overflow was addressed with improved input validation.
Affected: Safari (Apple); Webkitgtk; Wpe Webkit (Wpewebkit), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 3, 2026.
Yes. It was added on Mar 5, 2026 with a federal remediation due date of Mar 26, 2026.
Public exploit code is available.
Fixed versions are available, including Ipados 15.2, Iphone OS 15.2, macOS 12.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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