CVE-2026-39870
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 · uneditedThe issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5. Processing a maliciously crafted image may corrupt process memory.
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 confidenceA memory corruption vulnerability in macOS image processing allows a maliciously crafted image to corrupt process memory during parsing, potentially leading to arbitrary code execution. The issue was addressed with improved memory handling bounds checks or allocation management.
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>= 14.0, < 14.8.7>= 15.0, < 15.7.7>= 26.0, < 26.5CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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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Determine installed macOS versionRun 'sw_vers -productVersion' in Terminal or System Settings > General > AboutAffected if Version is 14.0 to 14.8.6, 15.0 to 15.7.6, or 26.0 to 26.4 (falls within any of the affected ranges)
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Confirm macOS build numberRun 'system_profiler SPSoftwareDataType' or check System Settings > General > About > Build NumberAffected if Build number corresponds to an unpatched version within the affected ranges above
If the macOS version is 14.x below 14.8.7, 15.x below 15.7.7, or 26.x below 26.5, the environment is vulnerable to memory corruption when processing crafted images.
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 · scoped14.8.715.7.726.5
Apply the relevant macOS security update (Sequoia 15.7.7, Sonoma 14.8.7, or Tahoe 26.5) to address the memory handling flaw in image processing. Avoid opening untrusted images from unknown sources until patched.
macOS Sonoma 14.8.7, macOS Sequoia 15.7.7, or macOS Tahoe 26.5 (depending on current major version)
- Back up important data using Time Machine or another backup method
- Check current macOS version by clicking Apple menu > About This Mac
- For macOS Sonoma (14.x): Go to System Settings > General > Software Update and install version 14.8.7 or later
- For macOS Sequoia (15.x): Go to System Settings > General > Software Update and install version 15.7.7 or later
- For macOS Tahoe (26.x): Go to System Settings > General > Software Update and install version 26.5 or later
- Alternatively, download the security update directly from https://support.apple.com/en-us/HT201222
- Restart the computer after the update completes
- Verify the update was successful by checking About This Mac again
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-39870 — 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-2026-39870 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