CVE-2026-20635

The issue was addressed with improved memory handling. This issue is fixed in Safari 26.3, iOS 18.7.5 and iPadOS 18.7.5, iOS 26.3 and iPadOS 26.3, macOS Tahoe 26.3, tvOS 26.3, visionOS 26.3, watchOS 26.3. Processing maliciously crafted web content may lead to an unexpected process crash.

Published: 2026-02-11 Last update: 2026-04-02 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-20635 is rated Low Risk (23.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-20635

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-20 0.03% 0.06% +0.02%
2 2026-02-12 0.03%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20635

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
2.8 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-20635

OS Trackers for CVE-2026-20635

vendor priority summary link
debian end-of-life CVE-2026-20635 end-of-life priority: Debian including 2 source packages (webkit2gtk, wpewebkit), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 7, open 3. https://security-tracker.debian.org/tracker/CVE-2026-20635
redhat high https://access.redhat.com/security/cve/CVE-2026-20635
suse medium https://www.suse.com/security/cve/CVE-2026-20635/
ubuntu medium CVE-2026-20635 medium priority: Ubuntu including 5 source packages (qtwebkit-opensource-src, qtwebkit-source, webkit2gtk, webkitgtk, wpewebkit), 36 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): ignored 14, DNE 13, needs-triage 4, needed 3, not-affected 1, released 1. https://ubuntu.com/security/CVE-2026-20635

Affected software / configurations for CVE-2026-20635

Vendor Product Version Raw CPE
apple safari < 26.3 cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
apple ipados < 18.7.5 cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple ipados >= 26.0, < 26.3 cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple iphone_os < 18.7.5 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple iphone_os >= 26.0, < 26.3 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple macos < 26.3 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple tvos < 26.3 cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
apple visionos < 26.3 cpe:2.3:o:apple:visionos:*:*:*:*:*:*:*:*
apple watchos < 26.3 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

References for CVE-2026-20635

URL Tags
https://support.apple.com/en-us/126346 Release Notes Vendor Advisory
https://support.apple.com/en-us/126347 Release Notes Vendor Advisory
https://support.apple.com/en-us/126348 Release Notes Vendor Advisory
https://support.apple.com/en-us/126351 Release Notes Vendor Advisory
https://support.apple.com/en-us/126352 Release Notes Vendor Advisory
https://support.apple.com/en-us/126353 Release Notes Vendor Advisory
https://support.apple.com/en-us/126354 Release Notes Vendor Advisory
cvelogic Threat Intelligence