OpenBSD up to 2026-06-18 MPLS sys/netmpls/mpls_input.c mpls_do_error out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k1.94+

Summaryinfo

A vulnerability, which was classified as problematic, was found in OpenBSD up to 2026-06-18. This vulnerability affects the function mpls_do_error of the file sys/netmpls/mpls_input.c of the component MPLS Handler. The manipulation results in out-of-bounds. This vulnerability is identified as CVE-2026-56099. The attack can be executed remotely. There is not any exploit available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability classified as problematic has been found in OpenBSD up to 2026-06-18. Affected is the function mpls_do_error of the file sys/netmpls/mpls_input.c of the component MPLS Handler. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality. CVE summarizes:

OpenBSD before commit 6a23123 (2026-06-18) contains an out-of-bounds read vulnerability in the mpls_do_error function within sys/netmpls/mpls_input.c that allows remote attackers to disclose kernel stack memory by sending crafted MPLS frames with 16 labels and no Bottom-of-Stack bit set.

The advisory is shared for download at pop.argus-systems.ai. This vulnerability is traded as CVE-2026-56099 since 06/18/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/19/2026).

Applying the patch 6a23123ec05f1eb29cfcaae0f3a468b2e1983cfd is able to eliminate this problem. The bugfix is ready for download at github.com.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

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 (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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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
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 6a23123ec05f1eb29cfcaae0f3a468b2e1983cfd

Timelineinfo

06/18/2026 CVE reserved
06/19/2026 +1 days Advisory disclosed
06/19/2026 +0 days VulDB entry created
06/19/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: pop.argus-systems.ai
Status: Confirmed

CVE: CVE-2026-56099 (🔒)
GCVE (CVE): GCVE-0-2026-56099
GCVE (VulDB): GCVE-100-372276

Entryinfo

Created: 06/19/2026 07:45
Changes: 06/19/2026 07:45 (79)
Complete: 🔍
Cache ID: 216::103

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