CVE-2021-39793
CVE-2021-39793 is a security flaw in Google Pixel, the software on Google’s Pixel phones. Someone who already has a foothold can use Google Pixel to take full control of the machine. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 11 Apr 2022.[1]
Google Pixel is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Google has published a fix or advice.
Description
CISA calls it an out-of-bounds write in Google Pixel. In its words: “Google Pixel contains a possible out-of-bounds write due to a logic error in the code that could lead to local escalation of privilege.”[1]
The CVE record adds: “In kbase_jd_user_buf_pin_pages of mali_kbase_mem.c, there is a possible out of bounds write due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-210470189References: N/A”[2]
The underlying weakness is out-of-bounds write (CWE-787), 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 NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Google’s advisory has them[3]. CISA names the product as Google Pixel.
Every device with Google Pixel needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 11 Apr 2022, 26 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 2 May 2022 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 under 1%. That’s in the top 48% 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
Google has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update Google Pixel now.On Android: Settings, then System or Software update. Phones only get these fixes while their maker still supports them. Then turn on automatic updates, so the next fix arrives on its own.
- 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 under 1%.[4] |
See also
Other Google Pixel flaws
- CVE-2026-58704: improper authorization ·
Other Google flaws
- CVE-2026-111497, Google Brotli: unchecked return value ·
- CVE-2026-87491, Chrome and other Chromium browsers: out of bounds write ·
- CVE-2026-85046, Chrome and other Chromium browsers: type confusion ·
- CVE-2026-11645, Chrome and other Chromium browsers: out-of-bounds read and write ·
- CVE-2026-5281, Google Dawn: use-after-free ·
Other out-of-bounds write flaws
- CVE-2026-86950, Apple devices: out-of-bounds write ·
- CVE-2026-53266, Linux Kernel: out-of-bounds write ·
- CVE-2026-53362, Linux Kernel: unspecified ·
- CVE-2022-0995, Linux Kernel: out-of-bounds write ·
- CVE-2026-0300, Palo Alto Networks PAN-OS: out-of-bounds write ·
Added the same day
- CVE-2022-23176, WatchGuard Firebox and XTM: privilege escalation ·
- CVE-2021-42287, Microsoft Active Directory: domain services privilege escalation ·
- CVE-2021-42278, Microsoft Active Directory: domain services privilege escalation ·
- CVE-2021-27852, Checkbox Survey: survey deserialization of untrusted data ·
- CVE-2021-22600, Linux Kernel: privilege escalation ·
Every Google flaw on CISA’s list · Everything added in April 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Google Pixel Out-of-Bounds Write Vulnerability”. Known Exploited Vulnerabilities Catalog, added 11 Apr 2022.
- ^ National Institute of Standards and Technology. “CVE-2021-39793 Detail”. National Vulnerability Database, published 16 Mar 2022.
- ^ Google. Advisories and fixes: source.android.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.007, percentile 52.6, 31 Oct 2026.
- CVE Program. “CVE-2021-39793”. 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.