CVE-2026-106121 — RabbitMQ: JSONReader in the default JSON-RPC mapper never terminates on truncated input, causing DoS
The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.37.0, com.rabbitmq.tools.json.JSONReader.read() fails to terminate when input ends inside a quoted string or a line comment because its string and whitespace scanners do not stop at CharacterIterator.DONE. The default DefaultJsonRpcMapper passes JSON-RPC message bodies to this parser for JsonRpcServer and client replies. A truncated string causes the parser to append replacement end markers until heap exhaustion, while a line comment without a terminating newline can keep a thread consuming CPU indefinitely, resulting in denial of service. This issue is fixed in version 5.37.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (high)+6
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Com.rabbitmq Amqp-client, Rabbitmq Rabbitmq-java-client, Vmware Rabbitmq Java Client).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Com.rabbitmq | Amqp-client | version < 5.36.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Rabbitmq | Rabbitmq-java-client | version < 5.36.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Vmware | Rabbitmq Java Client | < 5.37.0 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 4.9 | CVSS 3.1 | Medium | 1.2 | 3.6 | security-advisories@github.com via NIST National Vulnerability Database |
| 4.9 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.50%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · rabbitmq/rabbitmq-java-client, com.rabbitmq/amqp-client
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 7.5
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-106122 RabbitMQ: Malformed UTF-8 in shortstr properties permanently disables RPC consumers 9d
- Medium CVE-2026-106123 RabbitMQ Java client: plaintext broker credentials leaked in exception message from ConnectionFactoryConfigurator.load() 9d
- High CVE-2026-75516 RabbitMQ Java client: Frame-level OOM: Math.min(maxInboundMessageBodySize, 0) defeats frame size enforcement 29d
- High CVE-2026-69219 RabbitMQ Java client ValueReader: Oversized LongString/bytes length triggers OOM via unchecked allocation Aug 18, 2026
- High CVE-2026-69220 RabbitMQ Java client ValueReader: Unbounded recursive table/array nesting causes StackOverflowError DoS Aug 18, 2026
- Medium CVE-2026-63335 RabbitMQ Java client malformed body frame triggers raw command assembler exception Aug 18, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-106121 is "RabbitMQ: JSONReader in the default JSON-RPC mapper never terminates on truncated input, causing DoS", rated High. It affects Amqp-client (Com.rabbitmq); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 0.50% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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