Exim up to 4.99.1 JSON out-of-bounds

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k0.00

Summaryinfo

A vulnerability was found in Exim up to 4.99.1. It has been declared as critical. Affected by this issue is some unknown functionality of the component JSON Handler. Executing a manipulation can lead to out-of-bounds. The identification of this vulnerability is CVE-2026-40685. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Exim up to 4.99.1. It has been declared as critical. This vulnerability affects some unknown processing of the component JSON Handler. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability.

The advisory is available at seclists.org. This vulnerability was named CVE-2026-40685. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available.

The vulnerability scanner Nessus provides a plugin with the ID 312296 (Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : Exim vulnerabilities (USN-8228-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.99.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (312296). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 312296
Nessus Name: Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : Exim vulnerabilities (USN-8228-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Exim 4.99.2

Timelineinfo

04/30/2026 Advisory disclosed
04/30/2026 +0 days VulDB entry created
05/06/2026 +6 days VulDB entry last update

Sourcesinfo

Advisory: seclists.org
Status: Confirmed
Confirmation: 🔒

CVE: CVE-2026-40685 (🔒)
GCVE (CVE): GCVE-0-2026-40685
GCVE (VulDB): GCVE-100-360394

Entryinfo

Created: 04/30/2026 23:15
Updated: 05/06/2026 15:09
Changes: 04/30/2026 23:15 (53), 05/06/2026 15:09 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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