CVE-2026-67591: Apache Qpid ProtonJ2 · Unthrottled Resource Allocation
Affects Apache Qpid ProtonJ2Source CVE Database V5
Not known to be exploited · CVSS 6.5 Medium · fixed in 1.2.0 : update Apache Qpid ProtonJ2 when convenient.
Data as of 3 Nov 2026, 22:58 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.2.0
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 5 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software FoundationApache Qpid ProtonJ2 | Affected
| Fixed in– |
MavenApache Software Foundation/org.apache.qpid:protonj2pkg:maven/Apache Software Foundation/org.apache.qpid:protonj2Other threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users should upgrade Apache Qpid ProtonJ2 to version 1.2.0 or later, where this issue is fixed. No other mitigations or temporary workarounds are indicated. Patch status is confirmed by the vendor's recommendation to upgrade.
Description
An authenticated attacker could exceed the session flow control incoming window potentially leading to denial of service. This issue affects Apache Qpid ProtonJ2: through 1.1.0. Users are recommended to upgrade to version 1.2.0, which fixes the issue.