CVE-2026-20700
CVE-2026-20700 is a security flaw in Apple devices, the software on Apple’s iPhones, iPads and Macs. Attackers can run their own code on Apple devices. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 12 Feb 2026.[1]
Apple devices is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Fixed in version 26.3.
Description
CISA calls it a multiple buffer overflow in Apple Multiple Products. In its words: “Apple iOS, macOS, tvOS, watchOS, and visionOS contain an improper restriction of operations within the bounds of a memory buffer vulnerability that could allow an attacker with memory write the capability to execute arbitrary code.”[1]
The CVE record adds: “A memory corruption issue was addressed with improved state management. This issue is fixed in iOS 26.3 and iPadOS 26.3, macOS Tahoe 26.3, tvOS 26.3, visionOS 26.3, watchOS 26.3. An attacker with memory write capability may be able to execute arbitrary code. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals on versions of iOS before iOS 26. CVE-2025-14174 and CVE-2025-43529 were also issued in response to this report.”[2]
The underlying weakness is memory buffer error (CWE-119), in MITRE’s list of common software weaknesses.
It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| iOS and iPadOS | 26.3 |
| macOS | 26.3 |
| tvOS | 26.3 |
| visionOS | 26.3 |
| watchOS | 26.3 |
Every device with Apple devices needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 12 Feb 2026, within a day of it being made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 5 Mar 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 2%. That’s in the top 24% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Apple has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”[1]
- Update Apple devices now.On iPhone and iPad: Settings, General, Software Update. On a Mac: System Settings, General, Software Update. Install it on every Apple device in the house. Then turn on automatic updates, so the next fix arrives on its own.
- Check you’re on 26.3 or later.Fixed in version 26.3. Anything older is what attackers are going after.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 2%.[4] |
See also
Other Apple devices flaws
- CVE-2026-86950: out-of-bounds write ·
- CVE-2025-43520: classic buffer overflow ·
- CVE-2025-43510: improper locking ·
- CVE-2025-31277: buffer overflow ·
- CVE-2023-43000: use-after-free ·
- CVE-2021-30952: integer overflow or wraparound ·
Other memory buffer error flaws
- CVE-2026-88779, Citrix NetScaler: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2026-88772, Citrix NetScaler: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2026-88771, Citrix NetScaler: improper input validation ·
- CVE-2026-8452, Citrix NetScaler ADC and NetScaler Gateway: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2009-3459, Adobe Acrobat and Reader: heap-based buffer overflow ·
Added the same day
- CVE-2025-40536, SolarWinds Web Help Desk: security control bypass ·
- CVE-2025-15556, Notepad++: download of code without integrity check ·
- CVE-2024-43468, Microsoft Configuration Manager: SQL injection ·
Every Apple flaw on CISA’s list · Everything added in February 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Apple Multiple Buffer Overflow Vulnerability”. Known Exploited Vulnerabilities Catalog, added 12 Feb 2026.
- ^ National Institute of Standards and Technology. “CVE-2026-20700 Detail”. National Vulnerability Database, published 11 Feb 2026.
- ^ Apple. Advisories and fixes: support.apple.com, support.apple.com, support.apple.com, support.apple.com, support.apple.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.017, percentile 76.9, 31 Oct 2026.
- CVE Program. “CVE-2026-20700”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.