MediumGHSA-pmjh-fq2x-6v4xCVE-2026-18149

undici vulnerable to Denial of Service via orphaned RetryHandler response body

Published 29 Sept 2026 · Updated 29 Sept 2026

Affected packages

undicinpm

Affected: >=7.11.0 <7.29.1
Fixed in: 7.29.1

Update to the fixed version for your release line, for example:npm install undici@7.29.1

undicinpm

Affected: >=8.0.0 <8.10.2
Fixed in: 8.10.2

Update to the fixed version for your release line, for example:npm install undici@8.10.2

Details

Impact

undici's RetryHandler can leave a response body pending indefinitely. When a retried request receives a non-retryable response after a truncated one, the original response.body held by the application is never settled, so reads such as response.body.text() hang and bodyTimeout does not fire. A malicious server can repeat this to accumulate pending promises and streams, leading to denial of service.

Patches

Patched in undici v7.29.1 and v8.10.2.

Workarounds

Impose an independent request deadline and destroy the response body when it expires. bodyTimeout alone does not prevent this.

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.