CVE-2026-34956

Summary

A flaw was found in Open vSwitch. When Open vSwitch is configured with a conntrack flow using FTP helpers over the userspace datapath, a remote attacker can send a specially crafted FTP stream with an EPASV command exceeding 255 characters. This heap access error can lead to a crash, resulting in a Denial of Service (DoS) for the affected system.

Affected Software

Weaknesses

• CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Workarounds

Optionally, avoid using alg=ftp flows. These are not usually configured.

ADP Enrichment

CVE Program Container

Additional References

• http://www.openwall.com/lists/oss-security/2026/03/31/15

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: partial

References

• https://access.redhat.com/security/cve/CVE-2026-34956
• https://bugzilla.redhat.com/show_bug.cgi?id=2453459

• ←Previous
• Next→