CVE catalog

CVE-2026-70368

A stack-based out-of-bounds read vulnerability exists in the "s_vlog" function of stunnel, when handling oversized log messages via "vsnprintf". A remote attacker with network access to a stunnel serv

[CVE catalog]

Severity
Medium · CVSS 6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Published
Source
[NVD] · [CVE record]
EPSS
0.35% · Oct 25, 2026

A stack-based out-of-bounds read vulnerability exists in the "s_vlog" function of stunnel, when handling oversized log messages via "vsnprintf". A remote attacker with network access to a stunnel service can send protocol inputs that trigger a log message longer than 1024 bytes, leading to an out-of-bounds stack read and a potential crash. In certain corner cases, the same vulnerability could be used to replace a series of trailing "\n" characters with "\0".

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

DistributionPackageReleaseVersionStatus
Debianstunnel4trixie3:5.74-2vulnerable
Debianstunnel4bookworm3:5.68-2+deb12u1vulnerable

Fixed-version evidence

DistributionPackageTypeReleaseFixed versionUrgencyOriginBugs
Debianstunnel4sourcetrixie(unfixed)not yet assignedNot reportedNot reported
Debianstunnel4sourcebookworm(unfixed)not yet assignedNot reportedNot reported

Notes

[trixie] stunnel4: Minor issue [bookworm] stunnel4: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

  • [stunnel4]Affected
    Details (2)

    • 3:5.68-2+deb12u1 · amd64 · bookworm

      Affected

      nvd · stunnel4 · debian · bookworm; nvd · stunnel4 · debian · 12

    • 3:5.68-2+deb12u1 · arm64 · bookworm

      Affected

      nvd · stunnel4 · debian · bookworm; nvd · stunnel4 · debian · 12

[Debian 13 (Trixie)]

  • [stunnel4]Affected
    Details (2)

    • 3:5.74-2 · amd64 · trixie

      Affected

      nvd · stunnel4 · debian · 13

    • 3:5.74-2 · arm64 · trixie

      Affected

      nvd · stunnel4 · debian · 13

Observed:

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]