PatchTheCVECVE-2006-0631: CRLF injection vulnerability in mailback.pl in Erik C
CVE-2006-0631 is a medium-severity flaw (CVSS 5.0) affecting mailback. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
CRLF injection vulnerability in mailback.pl in Erik C. Thauvin mailback allows remote attackers to use mailback as a "spam proxy" by modifying mail headers, including recipient e-mail addresses, via newline characters in the Subject field.
Why this priority
- Public exploit reference
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 5.0 (Medium) |
| EPSS exploit chance | 1.7% (top 23%) |
| CISA exploited list | No |
| Published | 2006-02-10 |
| Last modified | 2026-06-16 |
Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2006-0631?
mailback: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2006-0631 being exploited?
CVE-2006-0631 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2006-0631 affect?
CVE-2006-0631 affects mailback. Severity is medium (CVSS 5.0). CRLF injection vulnerability in mailback.pl in Erik C. Thauvin mailback allows remote attackers to use mailback as a "spam proxy" by modifying mail headers, including recipient e-mail addresses, via newline characters in the Subject field.
How urgent is CVE-2006-0631?
Priority 42/100. Public exploit reference