Exim up to 4.99.1 musl libc denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.1$0-$5k0.00

Summaryinfo

A vulnerability was found in Exim up to 4.99.1. It has been classified as problematic. Affected by this vulnerability is an unknown functionality of the component musl libc. Performing a manipulation results in denial of service. This vulnerability was named CVE-2026-40684. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Exim up to 4.99.1. It has been classified as problematic. This affects an unknown code block of the component musl libc. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability.

The advisory is shared at seclists.org. This vulnerability is uniquely identified as CVE-2026-40684. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 314336 (Debian dsa-6265 : exim4 - security update), 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 (314336). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
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: Denial of service
CWE: CWE-404
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: 314336
Nessus Name: Debian dsa-6265 : exim4 - security update

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
05/13/2026 +13 days VulDB entry last update

Sourcesinfo

Advisory: seclists.org
Status: Confirmed
Confirmation: 🔒

CVE: CVE-2026-40684 (🔒)
GCVE (CVE): GCVE-0-2026-40684
GCVE (VulDB): GCVE-100-360393

Entryinfo

Created: 04/30/2026 23:15
Updated: 05/13/2026 17:08
Changes: 04/30/2026 23:15 (53), 05/13/2026 17:08 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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