Cisco Secure Firewall Adaptive Security Appliance Software OSPF Protocol out-of-bounds write

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.9$5k-$25k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software. This affects an unknown function of the component OSPF Protocol Handler. Such manipulation leads to out-of-bounds write. This vulnerability is listed as CVE-2026-20023. The attack must be carried out from within the local network. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software (affected version unknown) and classified as critical. Affected by this issue is an unknown functionality of the component OSPF Protocol Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is availability. CVE summarizes:

A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to corrupt memory on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to memory corruption when parsing OSPF protocol packets. An attacker could exploit this vulnerability by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to cause memory corruption causing the affected device to reboot, resulting in a DoS condition.

The advisory is available at sec.cloudapps.cisco.com. This vulnerability is handled as CVE-2026-20023 since 10/08/2025. The exploitation is known to be difficult. The attack can only be done within the local network. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 05/05/2026).

Upgrading eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.0
VulDB Meta Temp Score: 5.9

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

NVD Base Score: 6.5
NVD Vector: 🔒

CNA Base Score: 6.1
CNA Vector (cisco): 🔒

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

10/08/2025 CVE reserved
03/05/2026 +148 days Advisory disclosed
03/05/2026 +0 days VulDB entry created
05/05/2026 +61 days VulDB entry last update

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-asaftd-ospf-ZH8PhbSW
Status: Confirmed

CVE: CVE-2026-20023 (🔒)
GCVE (CVE): GCVE-0-2026-20023
GCVE (VulDB): GCVE-100-348818

Entryinfo

Created: 03/05/2026 02:30
Updated: 05/05/2026 16:33
Changes: 03/05/2026 02:30 (64), 05/05/2026 16:33 (12)
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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