Description
Irssi before 0.8.15, when SSL is used, does not verify that the server hostname matches a domain name in the subject's Common Name (CN) field or a Subject Alternative Name field of the X.509 certificate, which allows man-in-the-middle attackers to spoof IRC servers via an arbitrary certificate.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | irssi | 0.8.15-1 | — |
| Debian 13 | irssi | 0.8.15-1 | — |
| Debian 12 | irssi | 0.8.15-1 | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | irssi | 0.8.20-3.1 | openSUSE-SU-2024:10455-1 |
Advisories 1
- openSUSE-SU-2024:10455-1 irssi-0.8.20-3.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- [oss-security] 20100412 Re: CVE request: irssi 0.8.15 mailing-list
- [oss-security] 20100413 Re: CVE request: irssi 0.8.15 mailing-list
- ADV-2010-0856 vdb-entry
- ADV-2010-1110 vdb-entry
- irssi-hostname-mitm(57790) vdb-entry
- ADV-2010-1107 vdb-entry
- ADV-2010-0987 vdb-entry
- SUSE-SR:2010:011 vendor-advisory
- [oss-security] 20100413 Re: CVE request: irssi 0.8.15 mailing-list
- 39620 third-party-advisory
- 39365 third-party-advisory
- USN-929-1 vendor-advisory
- http://irssi.org/news
- [oss-security] 20100411 CVE request: irssi 0.8.15 mailing-list
- SSA:2010-116-01 vendor-advisory
- FEDORA-2010-6629 vendor-advisory
- http://github.com/ensc/irssi-proxy/commit/85bbc05b21678e80423815d2ef1dfe26208491ab
- http://irssi.org/news/ChangeLog
- 39797 third-party-advisory