Google has released a Chrome 156 security update that fixes 52 vulnerabilities, four of them critical and 46 high severity, including a memory corruption flaw that allows code execution outside the browser sandbox. The update is a follow-up to the Chrome 156 release of October 22.
Chrome 156.0.8078.73 Builds for Windows, Mac and Linux
Chrome 156.0.8078.73 and .74 cover Windows and Mac, while .73 covers Linux. Versions before 156.0.8078.73 are affected. Google is rolling the update out over days to weeks, and other Chromium-based browsers are expected to follow with their own updates.
The Four Critical Chrome Vulnerabilities
The most severe is CVE-2026-118306, a memory corruption bug in the FileSystem component. A crafted HTML page can trigger it to run code outside the sandbox, the security boundary that normally confines a compromised page.
Critical Flaws That Run Code Inside the Sandbox
The other three critical bugs each allow code execution inside the sandbox. They are CVE-2026-118331 in FileAPI, CVE-2026-118348 in Skia and CVE-2026-118344 in Layout. Running inside the sandbox limits damage, but such flaws are commonly paired with a second bug that breaks out of it.
Memory Safety Dominates the Full List
Of the 52 vulnerabilities, 32 are memory corruption, use-after-free or out-of-bounds write bugs. That share, about 60 percent of the fixes, continues the pattern of memory safety problems making up most serious browser flaws.
AI Tools Credited With Finding Chrome Bugs
AI tools feature heavily in the credits. Researcher Xinyang Ge reported 16 of the flaws, and six of those are credited as assisted by Claude. OpenAI Codex Security found four more.
The crediting reflects AI-assisted code analysis moving into routine browser vulnerability research. The update does not describe how the tools were used in each case, only that they were part of the discovery process.
No Exploitation or Public Exploit
Google reports no exploitation of these flaws. No public proof-of-concept exists, and none of the vulnerabilities appears in the CISA Known Exploited Vulnerabilities catalog.
That status sets this release apart from emergency Chrome updates issued when attackers are using a zero-day. Here the fixes come from the regular flow of discovery and reporting, even though the number of high-severity entries is large.
Relationship to the Earlier Chrome 156 Release
The Chrome 156 release on October 22 fixed 353 flaws. The new update is a separate follow-up, and the two should not be confused. The new batch is much smaller but still includes one bug that escapes the sandbox, a category security teams watch closely.
Drive-By Risk From the CVE-2026-118306 Sandbox Escape
The affected population is the whole Chrome user base on desktop operating systems. The risk described in the impact assessment is drive-by: a user visiting a crafted page. Because the sandbox-escape bug requires only crafted HTML, no further interaction beyond loading the page is described.
Users need to update and restart the browser for the fixes to take effect, and the staged rollout means some machines will receive the build later than others. Until Chromium-based browsers ship their own builds, those products remain on code that includes the vulnerable components.
The release also shows how browser makers credit AI-assisted discovery. Naming Claude and OpenAI Codex Security in the credits gives a public count of how many bugs involved such tools: six of Xinyang Ge’s 16 reports and four from Codex Security. A 52-flaw follow-up published days after a 353-flaw release shows that large batches are arriving in quick succession, and that the first release did not exhaust the queue of reported issues.
Google has not reported any attacks on the 52 flaws, and the staged rollout means the exposure window differs by machine. The two critical categories, sandbox escape and in-sandbox code execution, matter differently: the first removes the browser’s main containment layer on its own, while the other three need help from a second flaw to reach the operating system. The fix covers Windows, Mac and Linux, so the population exposed spans all major desktop platforms.
