# CVE-2026-14587: Unathenticated connection can hold Bolt channel open

> Unauthenticated attackers can exhaust server resources by holding Bolt channels open via malformed handshake packets, causing denial of service.

- **Severity:** Medium 5.5 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Aug 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BIT-neo4j-2026-14587, BIT-neo4j-enterprise-2026-14587, GHSA-cwvv-9488-x4h5, MINI-2m62-8fpw-8j5p, MINI-2wpp-c69r-853x, MINI-48vw-8qw4-p8g8, MINI-4cgr-46x3-m39m, MINI-6mcf-mjg7-xw3v, MINI-6xx5-qhpx-22ch, MINI-9q4f-hgv3-r8jm, MINI-gprm-c992-3wfc, MINI-hjhf-cr88-7ffw, MINI-pmrm-c457-4chc, MINI-q2m5-253v-7c7f, MINI-q2vj-72wh-j4j7, MINI-q8fr-wqf9-g54c, MINI-xcv9-9fqq-xf3h

## What is CVE-2026-14587?

CVE-2026-14587 is a medium-severity denial of service vulnerability in neo4j Community Edition, published on 5 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Neo4j's Bolt modern handshake decoder treats an overlong capability bit mask the same way it treats a truncated bit mask. When an unauthenticated client sends a selected protocol version followed by 32 continuation bytes in the capability mask, the decoder resets the reader index and waits for more bytes instead of rejecting the protocol message and closing the channel.

Because the same unread bytes remain at the front of the decoder buffer, appending a terminating byte later does not recover the connection. The decoder re-reads the same first 32 continuation bytes, returns without producing a handshake-finalization message, and leaves the channel open.

This can be triggered before authentication by any client that can reach the Bolt connector.

Weakness: CWE-130 (Improper Handling of Length Parameter Inconsistency)

## Which versions are affected by CVE-2026-14587?

2 open source packages ship an affected version, including neo4j and neo4j-enterprise. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `neo4j` | Bitnami | From 5.0.0 | 5.26.29, 2026.7.0 |
| `neo4j-enterprise` | Bitnami | From 5.0.0 | 5.26.29, 2026.7.0 |

Products: Neo4j Neo4j.

## How do I fix CVE-2026-14587?

Upgrade neo4j to a fixed version for your release line: 5.26.29 or 2026.7.0.

## Is CVE-2026-14587 being exploited?

There is no known exploitation of CVE-2026-14587 in the wild and no public exploit code.

## Other vulnerabilities in neo4j Community Edition

- [CVE-2021-34371](https://insights.sbomify.com/CVE-2021-34371/): Deserialization of Untrusted Data in Neo4j (critical 9.8)
- [CVE-2018-18389](https://insights.sbomify.com/CVE-2018-18389/): Incorrect access control in Neo4j Enterprise Database Server via LDAP authentication (critical 9.8)
- [CVE-2013-7259](https://insights.sbomify.com/CVE-2013-7259/): Neo4J vulnerable to Cross-Site Request Forgery (medium 6.8)
- [CVE-2024-34517](https://insights.sbomify.com/CVE-2024-34517/): Neo4j Cypher component mishandles IMMUTABLE privileges (medium 6.5)
- [CVE-2026-1471](https://insights.sbomify.com/CVE-2026-1471/): Caching of authentication context (low 2.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-14587 and fix it if it is affected.

What it is: CVE-2026-14587 is a medium-severity denial of service vulnerability in neo4j Community Edition, published on 5 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-14587 in the wild and no public exploit code.

Affected packages and fixed versions:
- neo4j (Bitnami): affected from 5.0.0; fixed in 5.26.29, 2026.7.0
- neo4j-enterprise (Bitnami): affected from 5.0.0; fixed in 5.26.29, 2026.7.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-14587/ (Markdown: https://insights.sbomify.com/CVE-2026-14587/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-14587
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-14587
- OSV: https://osv.dev/vulnerability/CVE-2026-14587

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-14587/
Summaries are generated and may contain mistakes; the official description above is the record.