MEDIUM
CVE-2026-32239
CWE-190Published: March 12, 2026· Updated: Mar 18, 2026
6.5
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:13.6th
Official Description
Cap'n Proto is a data interchange format and capability-based RPC system. Prior to 1.4.0, a negative Content-Length value was converted to unsigned, treating it as an impossibly large length instead. In theory, this bug could enable HTTP request/response smuggling. This vulnerability is fixed in 1.4.0.
Technical Analysis
CVE-2026-32239 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
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Affected Vendors & Products
capnproto1 product
capnproto
Source: NVD CPE · 1 total CPE entries
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.
Official Patches & Advisories
All References (5)
Quick Facts
CVE IDCVE-2026-32239
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-190
CISA KEVNo
EPSS (30d)0.04%
Affected1 vendor
PublishedMar 12, 2026
Related CVEs (CWE-190)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-32239 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.