Safari: Uncontrolled Resource Consumption
CVE-2026-20652 is a high-severity uncontrolled resource consumption vulnerability in Safari from Apple, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 26.3 as the first without the flaw, so updating Safari to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Safari to 26.3 or a later version.
- Update iOS and iPadOS to 18.7.5 or 26.3, whichever matches your release line, or a later version.
- Update macOS to 26.3 or a later version.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
| CVSS 3.1 | 7.5 | High | CNA |
Official description
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, visionOS 26.3. A remote attacker may be able to cause a denial-of-service.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Uncontrolled Resource Consumption
The product does not properly control the allocation and maintenance of a limited resource.
How developers prevent this class of flaw
- Ensure that protocols have specific limits of scale placed on them.
- Ensure that all failures in resource allocation place the system into a safe posture.
More Uncontrolled Resource Consumption vulnerabilities (CWE-400)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- support.apple.com/en-us/126346Release Notes
- support.apple.com/en-us/126347Release Notes
- support.apple.com/en-us/126348Release Notes
- support.apple.com/en-us/126353Release Notes
- support.apple.com/en-us/126354Release Notes
Other references
- access.redhat.com/errata/RHSA-2026:10702
- access.redhat.com/errata/RHSA-2026:11329
- access.redhat.com/errata/RHSA-2026:11814
- access.redhat.com/errata/RHSA-2026:13845
- access.redhat.com/errata/RHSA-2026:14659
- access.redhat.com/errata/RHSA-2026:16056
- access.redhat.com/errata/RHSA-2026:16695
- access.redhat.com/errata/RHSA-2026:19206
- access.redhat.com/errata/RHSA-2026:19535
- access.redhat.com/errata/RHSA-2026:22136
- access.redhat.com/errata/RHSA-2026:9692
- access.redhat.com/security/cve/CVE-2026-20652
- bugzilla.redhat.com/show_bug.cgi?id=2448793
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-20652.json
Other vulnerabilities in Safari
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 10.0 Critical severity
- 8.8 High severity
- 8.8 High severity
Recent Uncontrolled Resource Consumption vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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