CVE-2026-5265 | Ovn: ovn: heap over-read in icmp error response generation - security issue

When generating an ICMP Destination Unreachable or Packet Too Big response, the handler copies a portion of the original packet into the ICMP error body using the IP header's self-declared total length (ip_tot_len for IPv4, ip6_plen for IPv6) without validating it against the actual packet buffer size. A VM can send a short packet with an inflated IP length field that triggers an ICMP error (e.g., by hitting a reject ACL), causing ovn-controller to read heap memory beyond the valid packet data and include it in the ICMP response sent back to the VM.

Published: 2026-04-24 Last update: 2026-06-01 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-5265 is rated Low Risk (30.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.04%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-5265

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-02 0.09% 0.04% -0.05%
2 2026-04-30 0.04% 0.09% +0.05%
3 2026-04-25 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-5265

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 4.2 [email protected]

Weakness enumeration for CVE-2026-5265

GitHub Security Advisory for CVE-2026-5265

GHSA-whr7-6788-jg2p · Severity: medium — When generating an ICMP Destination Unreachable or Packet Too Big response, the handler copies a...

OS Trackers for CVE-2026-5265

vendor priority summary link
debian not yet assigned CVE-2026-5265 not yet assigned priority: Debian including 1 source packages (ovn), 4 status rows across 4 suites (bookworm, forky, sid, trixie): open 2, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-5265
suse high CVE-2026-5265 severity important: SUSE including 4 source package names (libopenvswitch-2_11-0, libopenvswitch-2_8-0, openvswitch, openvswitch-devel), 9 product×package rows across 5 product lines (SUSE Linux Enterprise Server 12 SP4-LTSS, SUSE Linux Enterprise Server 12 SP5-LTSS, … (5 product lines)): Known Not Affected 9. https://www.suse.com/security/cve/CVE-2026-5265/
ubuntu medium CVE-2026-5265 medium priority: Ubuntu including 1 source packages (ovn), 6 status rows across 6 suites (focal, jammy, noble, questing, resolute, upstream): needs-triage 5, released 1. https://ubuntu.com/security/CVE-2026-5265

Affected software / configurations for CVE-2026-5265

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-5265

cvelogic Threat Intelligence