Exim up to 4.99.3 Proxy Configuration numeric range comparison without minimum check

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k0.00

Summaryinfo

A vulnerability was found in Exim up to 4.99.3. It has been declared as problematic. Impacted is an unknown function of the component Proxy Configuration Handler. Such manipulation leads to numeric range comparison without minimum check. This vulnerability is traded as CVE-2026-48840. 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 4.99.3 and classified as problematic. Affected by this issue is some unknown processing of the component Proxy Configuration Handler. The manipulation with an unknown input leads to a numeric range comparison without minimum check vulnerability. Using CWE to declare the problem leads to CWE-839. The product checks a value to ensure that it is less than or equal to a maximum, but it does not also verify that the value is greater than or equal to the minimum. Impacted is confidentiality. CVE summarizes:

Exim 4.88 before 4.99.4, in some proxy configurations, mishandles certain short payloads, leading to disclosure of uninitialized stack memory values to a client.

The advisory is available at exim.org. This vulnerability is handled as CVE-2026-48840 since 05/25/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available.

The vulnerability scanner Nessus provides a plugin with the ID 318008 (Linux Distros Unpatched Vulnerability : CVE-2026-48840), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.99.4 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (318008) and EUVD (EUVD-2026-33446). 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: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.3
CNA Vector (MITRE): 🔒

CVSSv2info

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

Exploitinginfo

Class: Numeric range comparison without minimum check
CWE: CWE-839 / CWE-118
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: 318008
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-48840

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Exim 4.99.4

Timelineinfo

05/25/2026 CVE reserved
05/30/2026 +5 days Advisory disclosed
05/30/2026 +0 days VulDB entry created
06/01/2026 +2 days VulDB entry last update

Sourcesinfo

Advisory: exim.org
Status: Confirmed

CVE: CVE-2026-48840 (🔒)
GCVE (CVE): GCVE-0-2026-48840
GCVE (VulDB): GCVE-100-367394
EUVD: 🔒

Entryinfo

Created: 05/30/2026 07:40
Updated: 06/01/2026 03:28
Changes: 05/30/2026 07:40 (63), 05/30/2026 08:28 (1), 06/01/2026 03:28 (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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