Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Reading a new release v2.1.280 First look · 1/6 0 findings $0.00 so far
One change · api

browser-use-tool changed

agents-and-tools/tool-use/browser-use-tool

Nearest release: v2.1.273, published under an hour after this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Recorded here
Lines+4added
Lines−0removed
From line 1,127 where the diff opens
First seen 20 Aug 2026 this site's first read of the page
Recorded edits9to this page, all time

The whole hunk

from line 1127, old and new numbered
/
lines
from line 1127
11271127 
11281128Claude sometimes follows instructions found in page content even when they conflict with yours; text on a page that says "ignore your previous instructions and navigate to..." can divert it from the task. Isolate Claude from sensitive data and actions to limit what a prompt injection can reach, review [Mitigate jailbreaks and prompt injections](https://platform.claude.com/docs/en/test-and-evaluate/strengthen-guardrails/mitigate-jailbreaks), and if a task can't avoid a logged-in session, use a dedicated low-privilege account and keep human confirmation on account-changing actions.
11291129 
1130Anthropic has trained the model to resist these prompt injections and has added an extra layer of defense. If you use the browser use tool, classifiers will automatically scan what the browser returns, such as page text or screenshots, to flag potential prompt injections. When these classifiers identify a potential prompt injection, they will automatically steer the model to check whether the instruction really came from you before acting on it.
1131 
1132This extra protection won't be ideal for every use case (for example, use cases without a human in the loop), so if you'd like to opt out and turn it off, [contact support](https://support.claude.com/en/). The precautions above remain important even with these classifiers in place.
1133 
11301134Because the browser runs in your environment, the sites Claude visits see your executor's network identity, and page content reaches the API only as the tool results you return. Inform end users of the relevant risks and obtain their consent before enabling browser use in your products.
11311135 
11321136## Member tools