CVE-2023-26430
Published Aug 2, 2023 · Updated Oct 23, 2026
Original summary
Normalized public record · Updated Oct 23, 2026
Attackers with access to user accounts can inject arbitrary control characters to SIEVE mail-filter rules. This could be abused to access SIEVE extension that are not allowed by App Suite or to inject rules which would break per-user filter processing, requiring manual cleanup of such rules. We have added sanitization to all mail-filter APIs to avoid forwardning control characters to subsystems. No publicly available exploits are known.
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
Attackers with access to user accounts can inject arbitrary control characters to SIEVE mail-filter rules. This could be abused to access SIEVE extension that are not allowed by App Suite or to inject rules which would break per-user filter processing, requiring manual cleanup of such rules. We have added sanitization to all mail-filter APIs to avoid forwardning control characters to subsystems. No publicly available exploits are known.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Aug 2, 2023 · Last refreshed Oct 23, 2026