diesel-async may expose uninitialized padding bytes for MySQL temporal columns

Exploitation

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

CVSS 4.0

2.0 · CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary diesel-async exposes uninitialized stack padding to safe code on every read of a MySQL DATE, TIME, DATETIME, or TIMESTAMP column. Reading that buffer is undefined behavior, and the leaked bytes can contain stale heap/stack contents, so this is both a soundness bug and a potential information-disclosure vector. Details In diesel-async/src/mysql/row.rs (lines 65-103), MysqlRow::get builds a MysqlTime from the parsed mysqlasync::Value and then fabricates the byte buffer that downstream FromSql impls expect like this: MysqlTime is #[repr(C)] with 3 bytes of padding after bool neg (Linux x8664, offsets 0x21..0x23). The literal construction leaves that padding uninitialized, and tovec() carries it into a Vec<u8 that becomes the MysqlValue's backing buffer, reachable from safe code via MysqlValue::asbytes() - &[u8]. diesel itself avoids this by going through MaybeUninit::<MysqlTime::zeroed() + ptr::copynonoverlapping (see diesel/src/mysql/value.rs:43-94); the same pattern would fix…

Published by the source

7 May 2026, 00:02 UTC

Last modified by the source

7 May 2026, 00:02 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-ff9q-rm55-q7qr

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# Patch Next advisory brief: GHSA-ff9q-rm55-q7qr

Advisory: diesel-async may expose uninitialized padding bytes for MySQL temporal columns
IDs: GHSA-ff9q-rm55-q7qr
Record: https://patchnext.com/advisories/ghsa-ff9q-rm55-q7qr (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: diesel-async 0.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io diesel-async: affected >= 0.1.0, < 0.9.0; fixed in 0.9.0

## Suggested inspection (read-only)
- crates.io diesel-async: 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 diesel-async.
- 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://github.com/advisories/GHSA-ff9q-rm55-q7qr (GitHub-reviewed advisory GHSA-ff9q-rm55-q7qr lists affected ranges: crates.io diesel-async >=0.1.0 <0.9.0)

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