Blocked 'font' from 'data:' CSP error

Description

We are receiving a very large amount of Sentry events (747k in the last 24h, 22 million in the last month) related to a violation of the font-src CSP policy: Blocked 'font' from 'data:'.

The errors happen for different pages and users without a defined pattern, however, most of the errors occur in Safari:

Note: We also have a Blocked 'font' from 'fonts.gstatic.com' error at https://new-sentry.gitlab.net/organizations/gitlab/issues/220362/ which could be related.

Sentry information

Sentry Issue: GITLABCOM-CLIENTSIDE-5W0G

{"csp-report":{"effective_directive":"font-src","blocked_uri":"data","document_uri":"https://gitlab.com/sarus-tech/sarus-data-spec/-/merge_requests/464","original_policy":"base-uri 'self'; child-src https://www.google.com/recaptcha/ https://www.recaptcha.net/ https://content.googleapis.com https://content-compute.googleapis.com https://content-cloudbilling.googleapis.com https://content-cloudresourcemanager.googleapis.com https://www.googletagmanager.com/ns.html https://*.zuora.com/apps/PublicHostedPageLite.do https://gitlab.com/admin/ https://gitlab.com/assets/ https://gitlab.com/-/speedscope/index.html https://gitlab.com/-/sandbox/ https://gitlab.com/assets/ blob: data:; connect-src 'self' https://gitlab.com wss://gitlab.com https://sentry.gitlab.net https://new-sentry.gitlab.net https://customers.gitlab.com https://snowplow.trx.gitlab.net https://sourcegraph.com snowplow.trx.gitlab.net https://sourcegraph.com/.api/ https://observe.gitlab.com; default-src 'self'; font-src 'self'; frame-ancestors 'self'; frame-src 'self' https://www.google.com/recaptcha/ https://www.recaptcha.net/ https://content.googleapis.com https://content-cloudresourcemanager.googleapis.com https://content-compute.googleapis.com https://content-cloudbilling.googleapis.com https://*.codesandbox.io https://customers.gitlab.com https://*.zuora.com/apps/PublicHostedPageLite.do https://observe.gitlab.com https://gitlab.com/users/sign_in https://gitlab.com/oauth/authorize; img-src * data: blob:; manifest-src 'self'; media-src 'self' data: blob: http: https:; object-src 'none'; report-uri https://new-sentry.gitlab.net/api/4/security/?sentry_key=f5573e26de8f4293b285e556c35dfd6e&sentry_environment=gprd; script-src 'strict-dynamic' 'self' 'unsafe-inline' 'unsafe-eval' https://www.google.com/recaptcha/ https://www.gstatic.com/recaptcha/ https://www.recaptcha.net/ https://apis.google.com https://*.zuora.com/apps/PublicHostedPageLite.do 'nonce-bs2mGbghgND+sXZLCVAJkQ=='; style-src 'self' 'unsafe-inline'; worker-src https://gitlab.com blob: data:; form-action 'self' https: http: https: http: http: https:","referrer":"https://gitlab.com/dashboard/merge_requests?reviewer_username=ngrislain","status_code":200,"violated_directive":"font-src","source_file":"https://gitlab.com/sarus-tech/sarus-data-spec/-/merge_requests/464","line_number":629,"script_sample":"","disposition":"enforce"}}

Blocked 'font' from 'data:'