CVE-2026-14587: neo4j Enterprise Edition · Improper Handling of Length Parameter Inconsistency
Affects neo4j Enterprise EditionSource CVE Database V5
Public exploit available · CVSS 5.5 Medium : upgrade to 2026.07 or 5.26.29 as a priority.
Data as of 3 Nov 2026, 22:58 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2026.07, 5.26.29
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:PExploitation evidence
Disclosed: evidence found.
CVE published 5 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Upgrade Enterprise Edition and Community Edition and neo4j to 2026.07 or 5.26.29.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| neo4jEnterprise Edition | Affected
| Fixed in
|
| neo4jEnterprise Edition | Affected
| Fixed in
|
| neo4jCommunity Edition | Affected
| Fixed in
|
| neo4jCommunity Edition | Affected
| Fixed in
|
GitHubneo4jpkg:github/neo4jOther 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
If you cannot patch yet, restricting access to the Bolt connector to trusted clients only may reduce exposure.
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.