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.
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.
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)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.3 | 3.1 | MEDIUM |
|
2.8 | 1.4 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| 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 |
| 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:*:*:*:*:*:*:*:* |
| 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 |