CVE-2026-77630Network attack vectorHinoki check available

Service hang via blocking DNS resolution

Published Oct 16, 2026 · Updated Oct 16, 2026

DoS in PUPnP libupnp before 22.0.4 allows remote attackers to hang UPnP service via hostnames in HTTP requests or GENA callbacks. In uri.c, parse_hostport synchronously calls getaddrinfo on untrusted hostnames while parse_uri processes inbound HTTP request targets and SUBSCRIBE CALLBACK headers. Exploitation requires access to the embedded HTTP miniserver or GENA subscription handler; slow DNS lookups occupy its bounded worker pool until resolver timeouts, interrupting UPnP service rather than crashing the process.

CVSS severity7.5
High
EPSS probability0.35%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

DoS in PUPnP libupnp before 22.0.4 allows remote attackers to hang UPnP service via hostnames in HTTP requests or GENA callbacks. In uri.c, parse_hostport synchronously calls getaddrinfo on untrusted hostnames while parse_uri processes inbound HTTP request targets and SUBSCRIBE CALLBACK headers. Exploitation requires access to the embedded HTTP miniserver or GENA subscription handler; slow DNS lookups occupy its bounded worker pool until resolver timeouts, interrupting UPnP service rather than crashing the process.

The record

CVE
CVE-2026-77630
Published
Oct 16, 2026
Updated
Oct 16, 2026
Vendor
PUPnP
Product
libupnp
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 22.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

PUPnP · libupnpversion=< 22.0.4

Published CVSS scores

7.5PUPnPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

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