Moleculer: Unauthenticated Denial of Service via negative length field in the TCP transporter packet parser
Only Moleculer nodes using the TCP transporter with a reachable listening port are exposed, in versions 0.15.0 up to 0.15.2 and below 0.14.36.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 0.15.2, 0.14.36
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.15.2, 0.14.36.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed, reachable over the network without a login · Data gap: Advisories don't say whether default setups are affected
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
CVE-2026-97705 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.5 (high) and affects moleculer; fixed in 0.15.2 and 0.14.36.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 25/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Fix
- Fixed in 0.15.2, 0.14.36
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Moleculer, a progressive microservices framework for Node.js, has a flaw in its TCP transporter packet parser that lets a remote attacker without logging in make every service in the affected process unresponsive until it is restarted. The TCP transporter must be enabled and reachable for the flaw to be exploitable, so it is not present in default setups.
Read the original description
Moleculer is a progressive microservices framework for Node.js. Prior to 0.14.36 and 0.15.2, Parser._write in src/transporters/tcp/parser.js used Buffer.prototype.readInt32BE to read a signed packet length, so a remote unauthenticated peer could supply a negative value that caused packet.slice(length) to return the unchanged buffer while the while (packet.length > 0) loop continued indefinitely. The synchronous loop blocked the Node.js event loop and made every service in the process unresponsive until restart. The TCP transporter must be enabled and reachable, and neither CRC validation nor maxPacketSize prevents the malformed length value. This issue is fixed in versions 0.14.36 and 0.15.2.
What to do
Upgrade to a fixed version: 0.15.2, 0.14.36.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- moleculerjs moleculer
From 0.15.0 · fixed in 0.15.2; fixed in 0.14.36
Evidence 5
- Advisory
- Repository
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-97705
Is CVE-2026-97705 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A peer that can reach the TCP transporter's listening port can send a packet with a negative length field. This makes the Node.js process hang in an infinite synchronous loop, blocking the event loop so every service in that process stops responding until it is restarted. No authentication is needed.Source: github.com
Which versions are affected by CVE-2026-97705?
moleculer: from 0.15.0 before 0.15.2; before 0.14.36.Source: cve.now feed data
Am I affected, and how do I check?
Moleculer versions 0.15.0 up to 0.15.2 and versions below 0.14.36 are listed as affected. To check, run npm ls moleculer to see the installed version, and check whether the broker configuration sets the TCP transporter.Source: github.com
How do I fix CVE-2026-97705?
Upgrade to 0.15.2 if you are on the 0.15 line, or to 0.14.36 if you are on the 0.14 line. These are the fixed versions listed for this vulnerability.Source: github.com