Skip to main content

Capnproto CVE-2026-32239

MEDIUM
Integer Overflow or Wraparound (CWE-190)
2026-03-12 security-advisories@github.com
Information Disclosure Integer Overflow Red Hat Capnproto Suse
6.5
CVSS 3.1 · GitHub Advisory
View

Vulnerability Assessment

Weakness
CWE
CWE-190
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Integer overflow checks
MITRE ATT&CK

1 technique across 1 tactic: Execution

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Sign in to read
Exploit ScenarioDerived

An attacker could exploit this vulnerability to HTTP request/response smuggling.
This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 12, 2026

n Proto is a data interchange format and capability-based RPC system. versions up to 1.4.0 is affected by integer overflow or wraparound.

RemediationAI

Fixed in version 1.4.0..

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Sign in to check
Technical ContextAI · show details

This vulnerability (CWE-190: Integer Overflow or Wraparound) affects n Proto is a data interchange format and capability-based RPC system.. 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.

Know when Capnproto gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources
Continue with Google Continue with GitHub

No credit card · 7-day full trial

Severity by source

GitHub Advisory PRIMARY 6.5 MEDIUM
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
SUSE MEDIUM
Red Hat 4.8 MEDIUM

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

DescriptionGitHub Advisory

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.

Executive ViewAI

Why It Matters

CVE-2026-32239 presents notable security risk, a integer overflow vulnerability rated CVSS 6.5. Exploitation could cause memory corruption or application crashes. Organizations should apply vendor updates when available and monitor for exploitation.

Business Impact: Moderate
Compensating Controls

Apply vendor patch. If patching is delayed: enable ASLR/DEP, apply network segmentation.

Threat Intelligence Overview

EPSS Score
0.0%
Top 86% exploitable
Data Quality
5 sources
Confidence: Medium
NVD CVE.org EPSS Vendor GitHub VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.0%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes

Priority Score

32
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +32
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Integer Overflow MEDIUM

Integer overflow occurs when an arithmetic operation produces a result that exceeds the maximum value a given integer type can store.

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Affected Products (CPE)GitHub Advisory

cpe:2.3:a:capnproto:capnproto:*:*:*:*:*:*:*:*

Related Vulnerabilities in Cap'n Proto Content-Length Integer Vulnerabilities

View all 2
CVE-2026-32240 MEDIUM
6.5

More in Capnproto

View all
CVE-2023-48230 CRITICAL POC
9.8 Nov 21

Cap'n Proto is a data interchange format and capability-based RPC system. Rated critical severity (CVSS 9.8), this vulne
CVE-2015-2311 CRITICAL
9.8 Aug 09

Integer underflow in Sandstorm Cap'n Proto before 0.4.1.1 and 0.5.x before 0.5.1.1 might allow remote peers to cause a d
CVE-2015-2310 CRITICAL
9.1 Aug 09

Integer overflow in layout.c++ in Sandstorm Cap'n Proto before 0.4.1.1 and 0.5.x before 0.5.1.1 allows remote peers to c
CVE-2017-7892 HIGH
7.5 Apr 17

Sandstorm Cap'n Proto before 0.5.3.1 allows remote crashes related to a compiler optimization. Rated high severity (CVSS
CVE-2015-2312 HIGH
7.5 Aug 09

Sandstorm Cap'n Proto before 0.4.1.1 and 0.5.x before 0.5.1.1 allows remote peers to cause a denial of service (CPU and

CVE-2015-2313 HIGH
7.5 Aug 09

Sandstorm Cap'n Proto before 0.4.1.1 and 0.5.x before 0.5.1.2, when an application invokes the totalSize method on an ob
CVE-2022-46149 MEDIUM
5.4 Nov 30

Cap'n Proto is a data interchange format and remote procedure call (RPC) system. Rated medium severity (CVSS 5.4), this

Same weakness CWE-190 – Integer Overflow or Wraparound

View all
CVE-2013-2729 CRITICAL POC
9.8
CVE-2015-8651 HIGH
8.8
CVE-2012-5054 HIGH POC
8.8
CVE-2014-0569 CRITICAL POC
9.3
CVE-2023-21716 CRITICAL POC
9.8
CVE-2017-3599 HIGH POC
7.5
CVE-2017-7529 HIGH
7.5
CVE-2016-1010 HIGH
8.8

Same technique Information Disclosure

View all
CVE-2019-2725 CRITICAL POC
9.8
CVE-2021-34523 CRITICAL POC
9.0
CVE-2013-2251 CRITICAL POC
9.8
CVE-2017-5638 CRITICAL POC
9.8
CVE-2025-24813 CRITICAL POC
9.8
CVE-2025-68613 HIGH POC
8.8
CVE-2015-1701 HIGH POC
7.8
CVE-2017-0147 HIGH POC
7.5

Vendor StatusVendor

SUSE

Severity: Medium
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Fixed
SUSE Linux Enterprise High Performance Computing 15 SP7 Fixed
SUSE Linux Enterprise Module for Desktop Applications 15 SP7 Fixed
SUSE Linux Enterprise Module for Package Hub 15 SP7 Fixed
SUSE Linux Enterprise Server 15 SP7 Fixed

References

Advisories & patches
ADVISORY https://ubuntu.com/security/notices/USN-8650-1 ADVISORY https://vuldb.com/?id.350772 REF https://capnproto.org/capnproto-c++-1.4.0.tar.gz REF https://capnproto.org/capnproto-c++-win32-1.4.0.zip REF https://github.com/capnproto/capnproto/commit/2744b3c012b4aa3c31cefb61ec656829fa5c0e36 REF https://github.com/capnproto/capnproto/commit/e929f0ba7901a6b8f4b5ba9a4db00af43288cbb0 REF https://github.com/capnproto/capnproto/security/advisories/GHSA-qjx3-pp3m-9jpm

Search Externally

GitHub PoC Exploit-DB PacketStorm Snyk Rapid7 Nuclei Templates Trickest PoC
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy