Vulnerability · RUSTSEC-2026-0343
Outgoing datagram buffer accounting can panic the sender in quinn-proto
Published Sep 14, 2026 · RustSec Rust · evidence confidence high
The limit on memory used to buffer outgoing datagrams, introduced in 0.11.17, subtracted an evicted datagram's size from the buffered byte counter twice when was called with (as in the crate does) while the buffer was full. Under sustained eviction the counter drifts below its true value: debug builds panic with an integer underflow, while release builds wrap the counter, drain the whole queue, and then panic on a desynchronization check in a later call. In , this panic occurs while the connection lock is held, poisoning it and causing a double panic (and thus an abort) when the connection is
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
RUSTSEC-2026-0343 is a unknown public vulnerability record for RustSec Rust. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether RustSec Rust is in your estate, then compare installed versions with the affected ranges. Affected version ranges have not been ingested yet. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: no CVSS/EPSS yet. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: rustsec. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Sep 14, 2026 · RustSec Advisory DB
Detected
The limit on memory used to buffer outgoing datagrams, introduced in 0.11.17, subtracted an evicted datagram's size from the buffered byte counter twice when was called with (as in the crate does) while the buffer was full. Under sustained eviction the counter drifts below its true value: debug builds panic with an integer underflow, while release builds wrap the counter, drain the whole queue, an
Sources
- RustSec Advisory DBVendor advisoryRUSTSEC-2026-0343
The limit on memory used to buffer outgoing datagrams, introduced in 0.11.17, subtracted an evicted datagram's size from the buffered byte counter twice when was called with (as in the crate does) while the buffer was full. Under sustained eviction the counter drifts below its tr
crates.io