Zero-length DATAGRAM frames bypass the receive buffer limit in quinn-proto

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

quinn-proto bounds its queue of received datagrams by charging each queued frame's payload length against `TransportConfig::datagram_receive_buffer_size`, evicting the oldest datagrams when the limit is exceeded. A DATAGRAM frame with an empty payload was charged zero bytes, so it never triggered eviction and was appended to the queue, which has no other bound. DATAGRAM frames are not subject to flow control. A peer that has completed the handshake can therefore send a stream of empty DATAGRAM frames and grow the receiver's heap without limit until the process is killed. An application that reads incoming datagrams but does so more slowly than the peer sends them is still affected. Receiving datagrams is enabled by default, so all endpoints that do not explicitly set `datagram_receive_buffer_size(None)` are affected. The send path had the same accounting flaw: an application could enqueue an unbounded number of empty outgoing datagrams without ever receiving…

Published by the source

17 Aug 2026, 12:00 UTC

Last modified by the source

12 Oct 2026, 18:15 UTC

Source last checked

23 Oct 2026, 22:04 UTC

1. Revision 1 · created · 24 Oct 2026

   Published from osv record RUSTSEC-2026-0342

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# Patch Next advisory brief: GHSA-2hv7-gw8g-gpq5

Advisory: Zero-length DATAGRAM frames bypass the receive buffer limit in quinn-proto
IDs: GHSA-2hv7-gw8g-gpq5
Record: https://patchnext.com/advisories/rustsec-2026-0342 (revision 1, source checked 23 Oct 2026, 22:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: quinn-proto 0.11.17. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io quinn-proto: affected >= 0.5.0, < 0.11.17; fixed in 0.11.17

## Suggested inspection (read-only)
- crates.io quinn-proto: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on quinn-proto.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/RUSTSEC-2026-0342 (OSV record RUSTSEC-2026-0342 lists affected ranges: crates.io quinn-proto >=0.5.0 <0.11.17 (fixed))

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