CVE-2024-27834
CVE-2024-27834 is a security flaw in Apple devices, the software on Apple’s iPhones, iPads and Macs. Attackers can get into Apple devices without a valid password. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 4 Nov 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 17.5, 16.7.8, 14.5 and 10.5.
Description
CISA calls it an improper authentication in Apple Multiple Products. In its words: “Apple iOS, iPadOS, macOS, Safari, tvOS and watchOS 10.5 contain an improper authentication vulnerability which could allow an attacker with arbitrary read and write capability to bypass pointer authentication.”[1]
The CVE record adds: “The issue was addressed with improved checks. This issue is fixed in Safari 17.5, iOS 16.7.8 and iPadOS 16.7.8, iOS 17.5 and iPadOS 17.5, macOS Sonoma 14.5, tvOS 17.5, watchOS 10.5. An attacker with arbitrary read and write capability may be able to bypass Pointer Authentication.”[2]
The underlying weakness is improper authentication (CWE-287), in MITRE’s list of common software weaknesses.
It scores 5.5 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by NVD 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 |
|---|---|
| Safari | 17.5 |
| iOS and iPadOS | 16.7.8 |
| iOS and iPadOS | 17.5 |
| macOS | 14.5 |
| tvOS | 17.5 |
| watchOS | 10.5 |
Every device with Apple devices needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 4 Nov 2026, 904 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 18 Nov 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 26% 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 in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes).”[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 17.5 or later.Fixed in version 17.5, 16.7.8, 14.5 and 10.5. 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 5.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 2%.[4] | |
| CISA’s deadline for US government agencies to fix it.[1] |
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 improper authentication flaws
- CVE-2026-105133, AhsayCBS: improper authentication ·
- CVE-2026-42018, JFrog Artifactory: improper authentication ·
- CVE-2026-82329, JFrog Artifactory: improper authentication ·
- CVE-2026-59822, BerriAI LiteLLM: improper authentication ·
- CVE-2023-49105, ownCloud: improper authentication ·
Every Apple flaw on CISA’s list · Everything added in November 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Apple Multiple Products Improper Authentication Vulnerability”. Known Exploited Vulnerabilities Catalog, added 4 Nov 2026.
- ^ National Institute of Standards and Technology. “CVE-2024-27834 Detail”. National Vulnerability Database, published 14 May 2024.
- ^ Apple. Advisories and fixes: support.apple.com, support.apple.com, support.apple.com, support.apple.com, support.apple.com, and 3 more on NVD’s record.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.015, percentile 74.5, 7 Nov 2026.
- CVE Program. “CVE-2024-27834”. The official CVE record.
This article is built from CISA’s catalog (version 2026.11.06), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.