CVE-2026-2303VulnerabilityPublished 10 Feb 2026

CVE-2026-2303: MongoDB Go Driver · Permissive List of Allowed Inputs

Affects MongoDB Go DriverSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium : upgrade to 2.4.2 or 1.17.7 when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.4.2, 1.17.7

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: Passive
Vulnerable system confidentiality: None
Vulnerable system integrity: High
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade MongoDB Go Driver to 2.4.2 or 1.17.7.

Affected software

Product	Affected	Fixed in
MongoDB IncMongoDB Go Driver	Affected >=1.0.0 <1.17.7 >=2.0.0 <2.4.2	Fixed in 2.4.2 1.17.7

AI-suggested

To mitigate CVE-2026-2303, European organizations should: 1) Monitor MongoDB Go Driver usage and identify applications using versions 1.0.0 or 2.0.0 with Kerberos authentication on Linux/macOS. 2) Apply vendor patches immediately once available; if no patches exist, consider upgrading to a newer driver version that addresses this issue. 3) Implement strict input validation and sanitization around GSSAPI authentication data to prevent malformed buffers. 4) Employ runtime memory protection tools such as AddressSanitizer or similar to detect out-of-bounds reads during testing and staging. 5) Restrict network access to MongoDB services requiring Kerberos authentication to trusted hosts and networks, reducing exposure. 6) Educate users to avoid unsolicited interactions that could trigger the vulnerability. 7) Enable detailed logging and monitoring of authentication failures or unusual memory access patterns to detect exploitation attempts. 8) Consider isolating critical MongoDB instances in hardened environments with limited user interaction. These steps go beyond generic advice by focusing on the specific nature of the vulnerability and the environment in which it occurs.

Description

The mongo-go-driver repository contains CGo bindings for GSSAPI (Kerberos) authentication on Linux and macOS. The C wrapper implementation contains a heap out-of-bounds read vulnerability due to incorrect assumptions about string termination in the GSSAPI standard. Since GSSAPI buffers are not guaranteed to be null-terminated or have extra padding, this results in reading one byte past the allocated heap buffer.

Impact

For European organizations, the impact of CVE-2026-2303 can be significant in environments where MongoDB Go Driver is used with Kerberos authentication on Linux or macOS. The heap out-of-bounds read can lead to unintended memory disclosure, potentially exposing sensitive authentication tokens or other confidential data. This could facilitate further attacks such as credential theft or lateral movement within networks. Although the vulnerability does not allow direct code execution or privilege escalation, the confidentiality impact is high, which is critical for compliance with GDPR and other data protection regulations in Europe. Additionally, application instability or crashes caused by this vulnerability could disrupt business operations. Organizations in sectors with high security requirements, such as finance, healthcare, and government, are particularly at risk. The requirement for user interaction and low privileges reduces the attack surface somewhat, but the network attack vector means remote exploitation is possible if user interaction can be induced. Overall, the vulnerability poses a moderate risk that must be addressed to maintain secure authentication and data confidentiality.

CWE-183Permissive List of Allowed Inputs (opens in a new tab)
Base weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive - that is, it allows an input that is unsafe, leading to resultant weaknesses.
OWASP Cheat Sheets
Secure Design Principles (opens in a new tab)
Attack patterns
Double Encoding (opens in a new tab)
Using Leading 'Ghost' Character Sequences to Bypass Input Filters (opens in a new tab)
Exploiting Multiple Input Interpretation Layers (opens in a new tab)
Using Unicode Encoding to Bypass Validation Logic (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

jira.mongodb.org/browse/GODRIVER-3770 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Feb 2026, 10:05 UTC

WeaknessesCWE-183

Technical details

References

Community reviews

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