Vuln Signal Radar
public-safe defensive signal
MEDIUMpublic-safe

CVE-2026-16515

NVD: net_icmpv6_send_error() in subsys/net/ip/icmpv6.c implemented only one of the three RFC 4443 section 2.4 suppression rules (do not answer an ICMPv6 error with an ICMPv6 error). NVD: It did not check whether the triggering packet's source address identifies a single node (rule e.6) or whether the packet was sent to a multicast destination (rule e.3, whose only exceptions are Packet Too Big and Parameter Problem Code 2). NVD: Of the five call sites, only the port-unreachable path in subsys/net/ip/connection.c carried an equivalent guard of its own; the extension-header, unknown-next-header and fragmentation paths in subsys/net/ip/ipv6.c and subsys/net/ip/ipv6_fragment.c had none.

CVSS
4.7
Severity
MEDIUM
EPSS
0.0020 (9)
KEV
-

Source-published summary

NVD: net_icmpv6_send_error() in subsys/net/ip/icmpv6.c implemented only one of the three RFC 4443 section 2.4 suppression rules (do not answer an ICMPv6 error with an ICMPv6 error). NVD: It did not check whether the triggering packet's source address identifies a single node (rule e.6) or whether the packet was sent to a multicast destination (rule e.3, whose only exceptions are Packet Too Big and Parameter Problem Code 2). NVD: Of the five call sites, only the port-unreachable path in subsys/net/ip/connection.c carried an equivalent guard of its own; the extension-header, unknown-next-header and fragmentation paths in subsys/net/ip/ipv6.c and subsys/net/ip/ipv6_fragment.c had none.

Possible impact

Source describes remote exposure · authenticated boundary. Possible impact: This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for remote exposure · authenticated boundary.

Affected context

Affected product or version requires source confirmation.

Remediation / advisory

Remediation reference present; patch status requires confirmation in the linked advisory.

Why it matters

Source describes remote exposure · authenticated boundary. Possible impact: This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for remote exposure · authenticated boundary.; CVSS 4.7 (MEDIUM); EPSS percentile 9; not listed in KEV; Remediation reference present; patch status requires confirmation in the linked advisory; sources: NVD, OSV.

What to verify

Confirm affected product/version, vendor advisory, patch or mitigation, and exposure.

Exposure hint

remote exposure

Impact tags

remote exposure relevantauthenticated boundary review

Urgency reasons

vendor advisory presentrecent updateremediation reference present

Source-derived note

Summary derived from NVD / OSV description; unsafe procedural detail is not shown.

Redaction metadata

source summary used
True
fallback summary used
False
unsafe procedural detail present
false
raw source displayed
false
public summary redacted
true

Remediation handoff

Public-safe static handoff for human/Codex remediation planning. Scan, patch, external execution, and auto remediation are disabled.

Safety note

This radar shows source-published defensive context only. Exploit procedures, exploit strings, scanner commands, and auto-remediation are not provided.

Official references