CVE-2026-20643: apple ios and ipados Improper Input Validation
Vulnerability summary
CVE-2026-20643 is a medium (CVSS 5.4) Improper Input Validation vulnerability in apple ios and ipados. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 14 · Related 4Timeline
- 17-03-2026PublishedVulnerability first disclosed.
- 17-08-2026Last modifiedVulnerability information updated.
Description
A cross-origin issue in the Navigation API was addressed with improved input validation. This issue is fixed in Background Security Improvements for iOS, iPadOS, and macOS, Safari 26.4, iOS 18.7.7 and iPadOS 18.7.7, iOS 26.4 and iPadOS 26.4, macOS Tahoe 26.4, visionOS 26.4. Processing maliciously crafted web content may bypass Same Origin Policy.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- OSV · DebianEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- NVDNIST5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS trend
Probability
0.36%
Chance of exploitation in the next 30 days
Percentile
28%
Versus all other CVEs
30-day change
+0.01 pp
From 0.35% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
- CWE-346Origin Validation ErrorThe product does not properly verify that the source of data or communication is valid.
Affected systems
Apple6 products
- ios and ipados< 18.7.7 | < 26.3.1 (a) | < 26.4
- ipados< 26.3.1
- iphone_os< 26.3.1
- macos< 26.3.1 (a) | < 26.3.2 (a) | < 26.4 | < 26.3.1
- safari< 26.4
Ubuntu5 products
- qtwebkit-opensource-srcAll versions (No fix recorded)
- qtwebkit-sourceAll versions (No fix recorded)
- webkit2gtkAll versions (No fix recorded) | < 2.52.3-0ubuntu0.24.04.1 | < 2.52.3-0ubuntu0.25.10.1 | < 2.52.3-0ubuntu0.26.04.2
- webkitgtkAll versions (No fix recorded)
- wpewebkitAll versions (No fix recorded)
Debian2 products
- webkit2gtkAll versions (No fix recorded) | < 2.52.3-2~deb13u1 | < 2.52.1-1
- wpewebkitAll versions (No fix recorded) | < 2.52.1-1
3 vendors · 13 products
