CVE-2026-106429: Application denial of service via malformed KMS endpoint in MongoDB libmongocrypt
Noroxi assessment
Priority: Monitor (action score 28/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.29% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: MongoDB libmongocrypt 1.20.5.
Low priority for now. Upgrade to MongoDB libmongocrypt 1.20.5 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
An integer underflow in the KMS endpoint-parsing logic of MongoDB libmongocrypt can cause an allocation failure that terminates the application process. This can occur when an authenticated user modifies a key document in the key vault collection, or when an application accepts a KMS endpoint containing a colon after its path or query during key creation. The issue does not access memory outside its allocated bounds.
- Published
- Oct 8, 2026
- Updated
- Oct 8, 2026
- EPSS
- 0.2% · 21th percentile
- CWE
- CWE-191
Report tools
Action score
28
Low priority for now.
- CVSS
- 28 / 40 · 7.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · mongodb
- 7.1
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (mongodb). Independent of NVD's CPE analysis and usually ahead of it.
MongoDB libmongocrypt
- 1.1.0 and later · before 1.20.5affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | libmongocrypt | from 0 | — |
| Debian:14 | libmongocrypt | before 1.20.5-1 | 1.20.5-1 |
Same product
mongodb: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-106433Heap corruption via duplicate masterKey fields in MongoDB libmongocrypt34Monitor
- CVE-2026-84971Persistent client crash loop via undersized FLE2 insert-update ciphertext in decryption path28Monitor
- CVE-2026-114655KMS request injection via unsanitized key vault and provider values in libmongocrypt24Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-81523Aug 27, 2026 · Cross-tenant database retargeting via dot/NUL injection in namespace strings in libmongocrypt8Monitor
- ← EarlierCVE-2026-84962Sep 3, 2026 · Authenticated KMS request forgery via CRLF injection in GCP key identifier strings22Monitor
- Later →CVE-2026-106434Oct 8, 2026 · Unrecognized payload acceptance in explicit decryption in MongoDB libmongocrypt21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| MongoDB libmongocrypt | 1.20.5 | Vendor (CNA) |
| debian:libmongocrypt | 1.20.5-1 · Debian:14 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 13, 2026+36 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-191 · Integer Underflow (Wrap or Wraparound)CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Exploit maturity— → none
- Fix✗ → ✓
- SSVC exploitation— → none
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.