Vulnerability · RUSTSEC-2026-0343
Outgoing datagram buffer accounting can panic the sender in quinn-proto
Published Sep 14, 2026 · RustSec Rust
Open the advisory
Exploitation likelihood is not on this record for RUSTSEC-2026-0343. A missing EPSS score is not a low risk. Compare RustSec Rust with the linked advisory before you change production.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Awaiting synchronization with FIRST
- Remediation
- Not established
- Affected products
- RustSec Rust
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
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix RUSTSEC-2026-0343
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for RUSTSEC-2026-0343. A missing EPSS score is not a low risk. Compare RustSec Rust with the linked advisory before you change production.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
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
Freshness
Last verified in this catalog Unknown date. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.