VulnerabilityRUSTSEC-2026-0339 · quinn-proto
RUSTSEC-2026-0339: Unbounded growth of pending connection ID retirements in quinn-proto
Short answerA security vulnerability in the quinn-proto crate: Unbounded growth of pending connection ID retirements in quinn-proto. No severity score was published. Fixed in 0.11.17: update to a fixed version.
| Crate | quinn-proto |
|---|---|
| Type | Vulnerability (denial-of-service) |
| Affected versions | From 0.6.0 before 0.11.17. |
| Fixed in | 0.11.17 |
| Severity | not scored |
| Published | 2026-08-17 |
| Last changed | 2026-10-12 |
| Also known as | GHSA-hmxj-32vh-65vr |
What to do
- See which version you have:
cargo tree -i quinn-proto(it also shows which of your dependencies pulls it in). - Update within your version requirement:
cargo update -p quinn-proto. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for examplequinn-proto = "0.11.17") or update the dependency that pulls it in. - Check again with
cargo audit, or paste your Cargo.lock into our Cargo.toml checker.
Details from the advisory
When processing a NEW_CONNECTION_ID frame, quinn-proto queues a RETIRE_CONNECTION_ID frame for each connection ID that the peer asked it to retire. The normal path bounds this queue and closes the connection with a CONNECTION_ID_LIMIT_ERROR if the bound would be exceeded. However, the path handling a connection ID that had already been retired pushed onto the queue without applying the limit and without deduplicating.
A peer that has completed the handshake can first send a NEW_CONNECTION_ID frame with a large retire_prior_to value to advance the receiver's connection ID window, and then repeatedly send NEW_CONNECTION_ID frames with sequence numbers below that window. Each such frame adds another entry to the queue. The queue is only drained by sending RETIRE_CONNECTION_ID frames, which are subject to congestion control, so a peer that withholds acknowledgements can stall the drain while continuing to flood, growing the victim's memory use without bound.
The flaw was corrected in 0.11.17 by applying the same limit on the already-retired path.
Thanks to @scadastrangelove for reporting this issue.
References
- Package: crates.io/crates/quinn-proto
- Advisory: rustsec.org/advisories/RUSTSEC-2026-0339.html
- Web: github.com/quinn-rs/quinn/pull/2790
From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.
Other advisories for quinn-proto
- Vulnerability HighRUSTSEC-2023-0063 · 2023-09-21Denial of service in Quinn servers
- Vulnerability HighRUSTSEC-2024-0373 · 2024-09-02`Endpoint::retry()` calls can lead to panicking
- VulnerabilityRUSTSEC-2026-0037 · 2026-03-09Denial of service in Quinn endpoints
- Vulnerability HighRUSTSEC-2026-0185 · 2026-06-22 Remote memory exhaustion in quinn-proto from unbounded out-of-order stream reassembly
- VulnerabilityRUSTSEC-2026-0338 · 2026-09-14Remote peer can panic quinn-proto with zero-length STREAM frames during unordered reads
- Vulnerability HighRUSTSEC-2026-0340 · 2026-09-14Peer minimum ACK delay can panic quinn-proto when ACK_FREQUENCY transmission is enabled
- Vulnerability HighRUSTSEC-2026-0341 · 2026-08-17Stream reassembly memory-exhaustion guard in quinn-proto can be bypassed
- VulnerabilityRUSTSEC-2026-0342 · 2026-08-17Zero-length DATAGRAM frames bypass the receive buffer limit in quinn-proto
Up next
Same cratequinn-proto: security historyEvery advisory for this crate, and whether it is safe to use today.Read it next →Did this answer your question?