Memory exhaustion in MIME::Parser via truncated nested messages
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-407.
Summary
MIME::Parser in MIME-tools versions before 5.521 for Perl allows memory exhaustion. Each stored parser diagnostic is indented per nesting level, so when a deeply nested message ends without its closing boundaries, the stored diagnostics grow with the square of the nesting depth (CWE-407). The defaults place no limit on nesting depth. A remote unauthenticated attacker can exhaust memory and cause a denial of service by sending such a message.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
Description from the CNA
MIME::Parser versions before 5.521 for Perl allow memory exhaustion via indented error messages from a truncated, deeply nested message. Each stored parser diagnostic is indented by three spaces per nesting level. When a message nested N levels deep ends without its closing boundaries, every level logs an error at its own depth, so the stored diagnostics grow with the square of N. The defaults place no limit on nesting depth.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | MIME-tools | before 5.521 | 5.521 | Patch available | CNA |
- MIME-tools Vendor— Affected before 5.521 Fixed in 5.521 Patch available CNA
Remediation
Upgrade MIME-tools to version 5.521, which fixes this flaw. Red Hat Enterprise Linux 6 is affected, and the sources list no fixed version for it.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
- Fix · CNA MIME-tools Fixed in 5.521
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix yet |
Timeline
- 2026-10-28 Threatist record created from CVE-2026-116267
- 2026-10-28 Alias added: GHSA-4hx4-q2mp-7h24
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 CVSS score added · Red Hat
- 2026-11-05 CVSS score added · CISA ADP
- 2026-11-05 CISA SSVC decision points changed
References
Sources
- CVE-2026-116267 · CVE Program
- CVE-2026-116267 · NVD
- FIRST EPSS
- GHSA-4hx4-q2mp-7h24 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-116267 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences