MEDIUM
CVE-2026-40209
CWE-772Published: June 25, 2026· Updated: Jun 25, 2026
5.3
CVSS v3.1
EPSS:0.40%probability of exploitation in 30 daysPercentile:32.3th
Official Description
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.
Technical Analysis
CVE-2026-40209 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
All References (1)
Quick Facts
CVE IDCVE-2026-40209
CVSS Score5.3 / 10
SeverityMEDIUM
WeaknessCWE-772
CISA KEVNo
EPSS (30d)0.40%
PublishedJun 25, 2026
Related CVEs (CWE-772)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-40209 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.