[rudycelekli]

Bug

SecretSanitizer applies its patterns in registration order, and high_entropy is registered before jwt. high_entropy matches after =, : or a quote and stops at the first ., so for a JWT in any of those contexts it masks only the header (eyJ***J9). The jwt regex then no longer matches the rewritten string, so the payload and signature are written to the log in clear text. A standard header ({"alg":"HS256","typ":"JWT"}) is trivially guessable, so in practice the whole token is recoverable.

Trigger

Any log line or field containing:

{"id_token":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIn0.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"}

On main this is logged as:

{"id_token":"eyJ***J9.eyJzdWIiOiIxMjM0NTY3ODkwIn0.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"}

token=<jwt> and id_token: <jwt> leak the same way. A bare JWT (got <jwt>) is masked correctly, because high_entropy needs the =/:/quote context.

Fix

Register the jwt pattern before high_entropy. The JWT is then masked first (<header>.***.<last4>). Any remaining high-entropy header after a quote is still masked by high_entropy, as before. No pattern changes.

Test

TestSanitizer_JWTInKeyValueAndQuotedContexts checks that neither the payload nor the signature survives in the JSON, token=, id_token: and bare forms.

Commands run

• CGO_ENABLED=0 go test -count=1 ./internal/logs: ok
• With the fix reverted (git stash of sanitizer.go), the new test fails on 3 of 4 inputs with JWT payload/signature leaked. The bare form passes in both cases.
• gofmt -l on the edited files: no output

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

❌ Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
internal/logs/sanitizer.go	75.00%	1 Missing and 1 partial ⚠️

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[Dumbris]

Verified: the new test fails on main (payload and signature of a JWT after =, : or a quote were logged in clear) and passes here; race tests and CI lint for internal/logs are clean. Also checked combined with #1761 and #1762, and cross-reviewed. Masking the header twice once high_entropy runs afterwards is harmless.

[Dumbris]

Merged. Thank you, @rudycelekli! A JWT logged after =, : or inside quotes (an id_token in a JSON body, a token= query) had only its header masked, so the full token was recoverable from the logs. It is now masked whole.

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