iOS and iPadOS: Incorrect Comparison Logic Granularity
CVE-2026-28929 is a high-severity incorrect comparison logic granularity vulnerability in iOS and iPadOS 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 18.7.9 as the first without the flaw, so updating iOS and iPadOS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.41% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update iOS and iPadOS to 18.7.9 or a later version.
- Update macOS to 14.8.7 or 15.7.7 or 26.5, whichever matches your release line, or a later version.
- Update iPadOS to 18.7.9 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | iOS and iPadOS | before 18.7.9 | 18.7.9 |
| Apple | macOS | before 14.8.7; before 15.7.7; before 26.5 | 14.8.7, 15.7.7, 26.5 |
| Apple | iPadOS | before 18.7.9 | 18.7.9 |
| Apple | Iphone OS | before 18.7.9 | 18.7.9 |
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
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CISA (ADP).
Official description
A logic issue was addressed with improved checks. This issue is fixed in iOS 18.7.9 and iPadOS 18.7.9, macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5. Replying to an email could display remote images in Mail in Lockdown Mode.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Comparison Logic Granularity
The product's comparison logic is performed over a series of steps rather than across the entire string in one operation. If there is a comparison logic failure on one of these steps, the operation may be vulnerable to a timing attack that can result in the interception of the process for nefarious purposes.
How developers prevent this class of flaw
- The hardware designer should ensure that comparison logic is implemented so as to compare in one operation instead in smaller chunks.
More Incorrect Comparison Logic Granularity vulnerabilities (CWE-1254)
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/127111Release Notes
- support.apple.com/en-us/127115Release Notes
- support.apple.com/en-us/127116Release Notes
- support.apple.com/en-us/127117Release Notes
Other vulnerabilities in iOS and iPadOS
- 8.8 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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