This use-after-free in Safari's WebKit content pipeline carries a 5.5 CVSS, but the score measures current exploitability rather than exposure. The real signal is in the deployment geometry: Apple patched six platforms simultaneously, which is atypical. Their standard cadence for WebKit issues is sequential — macOS first, then iOS, then the others. Simultaneous rollout across Safari, iOS, iPadOS, macOS, tvOS, visionOS, and watchOS indicates Apple treated this as a credible threat requiring synchronized deployment, not a routine fix. That discrepancy between the 5.5 score and the six-platform urgency should inform your prioritization. The patch language — 'improved memory management' — is worth reading literally. This phrasing typically appears when a fuzzing oracle or static analysis tool found the symptom, the team patched the immediate dangling pointer, and moved on without fully auditing analogous lifetime patterns in surrounding code. WebKit has a documented history of UAF clusters: fuzzing surfaces one bug, the immediate fix lands, and structurally similar code paths with the same async object management patterns remain unhardened. Expect follow-on disclosures in adjacent code paths within months. More critically, this content pipeline powers WKWebView, which third-party applications embed for in-app browsing — banking apps, enterprise tools, and productivity software all run this same code without controlling the Safari version on the device. Your attack surface extends beyond users who open Safari directly. Check your dependencies for WKWebView integrations, particularly in mobile iOS/macOS applications or any Electron-based desktop app, and verify they pull the patched Safari/WebKit versions. The EPSS of 0.00107 correctly indicates no active weaponization today, but it measures market conditions, not inherent difficulty. If the development conditions that produced this UAF — shipping pressure on a rendering engine, the 'patch and move on' workflow — remain unchanged, structurally similar bugs likely exist in untested code paths. Treat this as a class vulnerability, not an isolated incident.
SafariWeb browser · Apple
CVE-2026-64718
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 use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 26.6, iOS 26.6 and iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, watchOS 26.6. Processing maliciously crafted web content may lead to an unexpected Safari crash.
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 analysisMemory is used after it has been freed, so its contents — now potentially attacker-controlled — drive the program's behaviour. With careful heap grooming this becomes code execution. The fix requires disciplined ownership of memory and often a targeted rework of the object lifecycle.
General guidance for the use after free class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
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
SafariWeb browser
< 26.6< 26.6< 26.6>= 26.0, < 26.6< 26.6< 26.6< 26.6CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
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 · scoped26.6
Upgrade to Safari 26.6, iOS 26.6, iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, or watchOS 26.6 as appropriate for your device
- For macOS: Open System Settings > General > Software Update and install macOS Tahoe 26.6, then update Safari to version 26.6 via the App Store
- For iOS/iPadOS: Go to Settings > General > Software Update and install iOS 26.6/iPadOS 26.6
- For tvOS: Go to Settings > General > Software Update and install tvOS 26.6
- For watchOS: Go to Settings > General > Software Update on the paired iPhone or directly on the watch to install watchOS 26.6
- For visionOS: Go to Settings > General > Software Update and install visionOS 26.6
- After updating, verify the Safari version by going to Safari > About Safari (macOS) or Settings > Safari > About (iOS/iPadOS)
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-64718 — 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 sourcesThis use-after-free in Safari's WebKit content pipeline carries a 5.5 CVSS, but the score measures current exploitability rather than exposure. The real signal is in the deployment geometry: Apple patched six platforms simultaneously, which is atypical. Their standard cadence for WebKit issues is sequential — macOS first, then iOS, then the others. Simultaneous rollout across Safari, iOS, iPadOS, macOS, tvOS, visionOS, and watchOS indicates Apple treated this as a credible threat requiring synchronized deployment, not a routine fix. That discrepancy between the 5.5 score and the six-platform urgency should inform your prioritization. The patch language — 'improved memory management' — is worth reading literally. This phrasing typically appears when a fuzzing oracle or static analysis tool found the symptom, the team patched the immediate dangling pointer, and moved on without fully auditing analogous lifetime patterns in surrounding code. WebKit has a documented history of UAF clusters: fuzzing surfaces one bug, the immediate fix lands, and structurally similar code paths with the same async object management patterns remain unhardened. Expect follow-on disclosures in adjacent code paths within months. More critically, this content pipeline powers WKWebView, which third-party applications embed for in-app browsing — banking apps, enterprise tools, and productivity software all run this same code without controlling the Safari version on the device. Your attack surface extends beyond users who open Safari directly. Check your dependencies for WKWebView integrations, particularly in mobile iOS/macOS applications or any Electron-based desktop app, and verify they pull the patched Safari/WebKit versions. The EPSS of 0.00107 correctly indicates no active weaponization today, but it measures market conditions, not inherent difficulty. If the development conditions that produced this UAF — shipping pressure on a rendering engine, the 'patch and move on' workflow — remain unchanged, structurally similar bugs likely exist in untested code paths. Treat this as a class vulnerability, not an isolated incident.
Practitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-64718 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
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