CVE-2026-20638
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA logic issue was addressed with improved checks. This issue is fixed in iOS 26.3 and iPadOS 26.3. A user with Live Caller ID app extensions turned off could have identifying information leaked to the extensions.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThis is a logic flaw in iOS 26.3/iPadOS 26.3 where Live Caller ID app extensions can receive user identifying information even when the user has explicitly disabled the Live Caller ID feature, resulting in unintended privacy leakage.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 26.3< 26.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check iOS/iPadOS versionGo to Settings > General > About and note the Version numberAffected if Version is less than 26.3 (e.g., 26.2, 26.1, etc.)
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Verify Live Caller ID feature existsGo to Settings > Phone (or Settings > Apps > Phone) and look for Live Caller ID or Call ID settingsAffected if Live Caller ID option is present on the device
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Confirm Live Caller ID extensions are installedGo to Settings > Phone > Call Blocking & Identification or Settings > Phone > Live Caller ID to see installed identification extensionsAffected if One or more Live Caller ID extensions are listed as installed
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Check if Live Caller ID is disabledIn the Live Caller ID settings, verify whether the user has disabled the feature (toggle off or unchecked)Affected if User has explicitly disabled Live Caller ID but extensions remain installed
You are affected if your device runs iOS/iPadOS version less than 26.3 and has Live Caller ID extensions installed, regardless of whether you have disabled the Live Caller ID feature, because the logic flaw allows extensions to receive user info even when disabled.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped26.3
Update to iOS 26.3/iPadOS 26.3 when released, as Apple has addressed this with improved logic checks to properly honor the user's preference to disable Live Caller ID extensions.
iOS 26.3 and iPadOS 26.3
- Check your current iOS version by going to Settings > General > About
- Back up your device data using iCloud or iTunes/Finder before updating
- Connect your device to Wi-Fi and power
- Go to Settings > General > Software Update
- Download and install iOS 26.3 or iPadOS 26.3 when available
- Restart your device if prompted to complete the installation
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20638 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-20638 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data