CVE-2026-4359: MongoDB C Driver · Improper neutralization of null byte or NUL character
Affects MongoDB C DriverSource CVE Database V5
Not known to be exploited · CVSS 2.0 Low : upgrade to 2.2.3 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.2.3
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 17 Mar 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 30 Oct 2026.
What to do
Upgrade MongoDB C Driver to 2.2.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MongoDB IncMongoDB C Driver | Affected
| Fixed in
|
AI-suggested
2) Employ network security controls such as TLS encryption and certificate pinning to prevent man-in-the-middle attacks and ensure the integrity of HTTP responses received by the MongoDB C Driver. 3) Restrict network access to trusted sources and minimize exposure of systems using the MongoDB C Driver to untrusted networks or third-party cloud servers. 4) Implement application-level error handling and watchdog mechanisms to detect and recover from driver crashes to maintain service continuity. 5) Conduct regular security assessments of third-party cloud providers and intermediaries to reduce the risk of compromised servers injecting malformed responses. 6) Consider using alternative MongoDB drivers or client libraries with more robust input validation if immediate patching is not feasible. These targeted mitigations will reduce the likelihood and impact of exploitation while maintaining operational stability.
Description
CVE-2026-4359 is a low-severity vulnerability in the MongoDB C Driver caused by improper neutralization of null byte characters (CWE-158). An attacker, such as a compromised third-party cloud server or a man-in-the-middle, can send a malformed HTTP response containing null bytes that triggers a crash in applications using this driver. Exploitation requires high privileges and user interaction, and the attack complexity is high. There are no known exploits in the wild, and no patches have been released yet. The vulnerability primarily impacts the availability of applications relying on the MongoDB C Driver by causing crashes, but it does not affect confidentiality or integrity. Countries with significant MongoDB usage and cloud infrastructure reliance are more likely to be affected. Overall, the threat is limited in scope and impact but should be addressed to maintain service stability.