CVE-2026-81523

Cross-tenant database retargeting via dot/NUL injection in namespace strings in libmongocrypt

2.0 LowFix available

A missing input-validation issue in MongoDB libmongocrypt's automatic-encryption context setup allows a caller-supplied database identifier to be accepted without sanitization. The resulting impact is limited to incorrect schema selection, which may lead to limited disclosure or modification of information handled by the application.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

0.10%Unchanged since Aug 28, 2026

What each source reports

CVE List Score used 2.0

Cross-tenant database retargeting via dot/NUL injection in namespace strings in libmongocrypt

Record: CVE-2026-81523
CVSS 4.0: 2.0 LowCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 4.4 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-74
Updated: 2026-11-02

EUVDEUVD-2026-67207 2.0

Record: EUVD-2026-67207
CVSS 4.0: 2.0 LowCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

NVD 2.0

Record: CVE-2026-81523
CVSS 4.0: 2.0 LowCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/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
CVSS 3.1: 4.4 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-74
Updated: 2026-11-02

OSV 2.0

Cross-tenant database retargeting via dot/NUL injection in namespace strings in libmongocrypt

Record: CVE-2026-81523
CVSS 4.0: 2.0 LowCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-74
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-81523 2.0

Record: DEBIAN-CVE-2026-81523
CVSS 4.0: 2.0 LowCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/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
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-81523 2.0

Record: UBUNTU-CVE-2026-81523
CVSS 4.0: 2.0 LowCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 4.4 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Updated: 2026-11-02

Affected products

mongodb libmongocrypt

Affected packages

Affected packages
Package	Affected	Fixed
`libmongocrypt` Debian:12	All versions, plus listed versions 1.10.0-11.10.1-11.11.0-11.12.0-11.13.0-1 Show 18 moreShow less 1.13.1-11.13.2-11.16.0-11.17.0-11.17.3-11.18.1-11.18.2-11.19.0-11.19.1-11.20.0-11.20.1-11.20.2-11.20.3-11.20.4-11.7.2-11.8.2-11.8.4-11.9.1-1	None known
`libmongocrypt` Debian:13	before 1.13.2-1+deb13u1, plus listed versions 1.13.2-1	1.13.2-1+deb13u1
`libmongocrypt` Debian:14	before 1.20.3-1, plus listed versions 1.13.2-11.16.0-11.17.0-11.17.3-11.18.1-1 Show 6 moreShow less 1.18.2-11.19.0-11.19.1-11.20.0-11.20.1-11.20.2-1	1.20.3-1
`libmongocrypt` Ubuntu:22.04:LTS	All versions, plus listed versions 1.2.1-11.2.2-11.3.0-11.3.0-1ubuntu1	None known
`libmongocrypt` Ubuntu:24.04:LTS	All versions, plus listed versions 1.7.2-11.8.2-11.8.4-11.8.4-1build21.8.4-1build3	None known
`libmongocrypt` Ubuntu:26.10	All versions, plus listed versions 1.17.0-11.19.0-11.19.1-11.20.0-11.20.1-1build11.20.2-1	None known
`libmongocrypt` Ubuntu:26.04:LTS	All versions, plus listed versions 1.13.2-11.17.0-1	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-81523 is a low vulnerability (CVSS 2.0) in Mongodb Libmongocrypt, published August 27, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.10%, the 0th percentile. Fixed in libmongocrypt 1.13.2-1+deb13u1.