FaucetSDN Ryu Denial of Service Vulnerability

published 2023-08-11 3 y ago modified 2026-07-07 4 mo ago also GHSA-4987-5p3p-9r27 , PYSEC-2026-1876 , EUVD-2023-2205

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.0%; EPSS 1.0% chance of exploitation in 30 days, percentile 61%
public exploits: 0; none known

An issue was discovered in OFPBundleCtrlMsg in parser.py in Faucet SDN Ryu version 4.34, allows remote attackers to cause a denial of service (DoS) (infinite loop).

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 2 y ago (2024-10-09)

Exploit prediction

0.95% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/faucetsdn/ryu/issues/118 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
pypi	ryu	<=4.34	no fix listed

Classification

Weakness

CWE-835 Loop with Unreachable Exit Condition
CWE-770 Allocation of Resources Without Limits or Throttling

References

github.com /faucetsdn/ryu/issues/118
web, exploit, issue-tracking
nvd.nist.gov /vuln/detail/CVE-2020-35139
advisory
github.com /faucetsdn/ryu
package
pypi.org /project/ryu
package
github.com /advisories/GHSA-4987-5p3p-9r27
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary