Stable Channel Update for Desktop

The Chrome team is delighted to announce the promotion of Chrome 91 to the stable channel for Windows, Mac and Linux. This will roll out over the coming days/weeks.



Chrome 91.0.4472.77 contains a number of fixes and improvements -- a list of changes is available in the log. Watch out for upcoming Chrome and Chromium blog posts about new features and big efforts delivered in 91.


Security Fixes and Rewards

Note: Access to bug details and links may be kept restricted until a majority of users are updated with a fix. We will also retain restrictions if the bug exists in a third party library that other projects similarly depend on, but haven’t yet fixed.


This update includes 32 security fixes. Below, we highlight fixes that were contributed by external researchers. Please see the Chrome Security Page for more information.


[$20000][1208721] High CVE-2021-30521: Heap buffer overflow in Autofill. Reported by ZhanJia Song on 2021-05-13

[$7500][1176218] High CVE-2021-30522: Use after free in WebAudio. Reported by Piotr Bania of Cisco Talos on 2021-02-09

[$7500][1187797] High CVE-2021-30523: Use after free in WebRTC. Reported by Tolyan Korniltsev on 2021-03-13

[$TBD][1197146] High CVE-2021-30524: Use after free in TabStrip. Reported by David Erceg on 2021-04-08

[$TBD][1197888] High CVE-2021-30525: Use after free in TabGroups. Reported by David Erceg on 2021-04-11

[$TBD][1198717] High CVE-2021-30526: Out of bounds write in TabStrip. Reported by David Erceg on 2021-04-13

[$TBD][1199198] High CVE-2021-30527: Use after free in WebUI. Reported by David Erceg on 2021-04-15

[$NA][1206329] High CVE-2021-30528: Use after free in WebAuthentication. Reported by Man Yue Mo of GitHub Security Lab on 2021-05-06

[$7500][1195278] Medium CVE-2021-30529: Use after free in Bookmarks. Reported by koocola (@alo_cook) and Nan Wang (@eternalsakura13) of 360 Alpha Lab on 2021-04-02

[$7500][1201033] Medium CVE-2021-30530: Out of bounds memory access in WebAudio. Reported by kkwon on 2021-04-21

[$5000][1115628] Medium CVE-2021-30531: Insufficient policy enforcement in Content Security Policy. Reported by Philip Papurt on 2020-08-12

[$5000][1117687] Medium CVE-2021-30532: Insufficient policy enforcement in Content Security Policy. Reported by Philip Papurt on 2020-08-18

[$5000][1145553] Medium CVE-2021-30533: Insufficient policy enforcement in PopupBlocker. Reported by Eliya Stein on 2020-11-04

[$3000][1151507] Medium CVE-2021-30534: Insufficient policy enforcement in iFrameSandbox. Reported by Alesandro Ortiz on 2020-11-20

[$1000][1194899] Medium CVE-2021-30535: Double free in ICU. Reported by nocma, leogan, cheneyxu of WeChat Open Platform Security Team on 2021-04-01

[$500][1145024] Medium CVE-2021-21212: Insufficient data validation in networking. Reported by Hugo Hue and Sze Yiu Chau of the Chinese University of Hong Kong on 2020-11-03

[$15000][1194358] Low CVE-2021-30536: Out of bounds read in V8. Reported by Chris Salls (@salls) on 2021-03-31

[$3000][830101] Low CVE-2021-30537: Insufficient policy enforcement in cookies. Reported by Jun Kokatsu (@shhnjk) on 2018-04-06

[$3000][1115045] Low CVE-2021-30538: Insufficient policy enforcement in content security policy. Reported by Tianze Ding (@D1iv3) of Tencent Security Xuanwu Lab on 2020-08-11

[$1000][971231] Low CVE-2021-30539: Insufficient policy enforcement in content security policy. Reported by unnamed researcher  on 2019-06-05

[$500][1184147] Low CVE-2021-30540: Incorrect security UI in payments. Reported by @retsew0x01 on 2021-03-03


We would also like to thank all security researchers that worked with us during the development cycle to prevent security bugs from ever reaching the stable channel.

As usual, our ongoing internal security work was responsible for a wide range of fixes:

  • [1213064] Various fixes from internal audits, fuzzing and other initiatives


Many of our security bugs are detected using AddressSanitizer, MemorySanitizer, UndefinedBehaviorSanitizer, Control Flow Integrity, libFuzzer, or AFL.


Prudhvikumar Bommana

Google Chrome