Vulnerability · RUSTSEC-2026-0337
Poly1305 panics or computes a wrong tag on attacker-chosen messages of 64 bytes or more
Published Oct 9, 2026 · RustSec Rust
Open the advisory
Exploitation likelihood is not on this record for RUSTSEC-2026-0337. 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
in absorbs messages of 64 bytes or more four blocks at a time, summing four products before one reduction. From 0.2.5 to 0.2.19 the reduction kept its carries in 32-bit integers, which four summed products can overflow when the message's bytes are large. This affects and , and everything built on them: the TLS and QUIC ChaCha20-Poly1305 suites in , HPKE with that cipher in , and the re-exports in and . What happens depends on how the crate was compiled: - With overflow checks on (any debug build, or a release profile with ) the multiplication panics, and under the process ends. The tag is comp
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix RUSTSEC-2026-0337
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-2026-0337. 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.
Oct 9, 2026 · RustSec Advisory DB
Detected
in absorbs messages of 64 bytes or more four blocks at a time, summing four products before one reduction. From 0.2.5 to 0.2.19 the reduction kept its carries in 32-bit integers, which four summed products can overflow when the message's bytes are large. This affects and , and everything built on them: the TLS and QUIC ChaCha20-Poly1305 suites in , HPKE with that cipher in , and the re-exports in
Sources
- RustSec Advisory DBVendor advisoryRUSTSEC-2026-0337
in absorbs messages of 64 bytes or more four blocks at a time, summing four products before one reduction. From 0.2.5 to 0.2.19 the reduction kept its carries in 32-bit integers, which four summed products can overflow when the message's bytes are large. This affects and , and ev
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.