
CVE catalog
CVE-2026-56016
CGI::Session::ID::md5 versions before 4.49 for Perl generate predictable session ids from low-entropy sources. The generate_id method builds the session id from a MD5 digest of the process id, the ep
- Severity
- High · CVSS 7.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.51% · Oct 25, 2026
CGI::Session::ID::md5 versions before 4.49 for Perl generate predictable session ids from low-entropy sources. The generate_id method builds the session id from a MD5 digest of the process id, the epoch time, and the built-in rand() function. All three are predictable, low-entropy sources: the PID is drawn from a small range, the epoch time can be guessed or read from the HTTP Date header, and Perl's rand() is unsuitable for security purposes because it is predictable and reversible. An attacker who predicts a session id can impersonate the corresponding session and bypass authentication.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | libcgi-session-perl | sid | 4.49-1 | fixed |
| Debian | libcgi-session-perl | forky | 4.49-1 | fixed |
| Debian | libcgi-session-perl | trixie | 4.48-4 | vulnerable |
| Debian | libcgi-session-perl | bookworm | 4.48-4 | vulnerable |
| Cpe | libcgi-session-perl | Not reported | Not reported | vulnerable |
| Alpine | perl-cgi-session | 3.24 | 4.49-r0 | fixed |
| Opensuse | perl-CGI-Session | tumbleweed | 4.490.0-1.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | libcgi-session-perl | source | sid | 4.49-1 | not yet assigned | Not reported | [1141197] |
| Debian | libcgi-session-perl | source | forky | 4.49-1 | not yet assigned | Not reported | [1141197] |
| Debian | libcgi-session-perl | source | trixie | (unfixed) | not yet assigned | Not reported | [1141197] |
| Debian | libcgi-session-perl | source | bookworm | (unfixed) | not yet assigned | Not reported | [1141197] |
| Alpine | perl-cgi-session | apk | 3.24 | 4.49-r0 | Not reported | ALPINE-CVE-2026-56016 | Not reported |
| Opensuse | perl-CGI-Session | rpm | tumbleweed | 4.490.0-1.1 | Not reported | OPENSUSE-SU-2026:11168-1 | Not reported |
Notes
[trixie] libcgi-session-perl: Minor issue [bookworm] libcgi-session-perl: Minor issue; predictable session IDs only practically exploitable under a persistent interpreter such as FastCGI or mod_perl
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libcgi-session-perl]Affected
Details (2)
4.48-4· all · bookwormAffected
nvd · libcgi-session-perl · debian · bookworm; nvd · libcgi-session-perl · debian · 12
4.48-4· all · bookwormAffected
nvd · libcgi-session-perl · debian · bookworm; nvd · libcgi-session-perl · debian · 12
[Debian 13 (Trixie)]
- [libcgi-session-perl]Affected
Details (2)
4.48-4· all · trixieAffected
nvd · libcgi-session-perl · debian · 13
4.48-4· all · trixieAffected
nvd · libcgi-session-perl · debian · 13
[openSUSE Tumbleweed]
- [perl-CGI-Session]Fixed
Source package: [perl-CGI-Session]
Details (1)
4.490.0-1.3· noarch · tumbleweedFixed · Fixed:
4.490.0-1.1nvd · perl-CGI-Session · opensuse · tumbleweed
Observed:
References
- [http://www.openwall.com/lists/oss-security/2026/07/01/6]
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11168-1.json]
- [https://metacpan.org/release/MARKSTOS/CGI-Session-4.49/changes]
- [https://metacpan.org/release/MARKSTOS/CGI-Session-4.49/source/lib/CGI/Session/ID/md5.pm]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-56016]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-56016]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-56016]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:11168-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-56016]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56016.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]