CVE WatchAug 11, 2026

CVE-2025-20333

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability

CVSS

9.9

Critical

EPSS

70.7%

p99

KEV

YES

Sep 25, 2025

Exploit Today

0-100

Published: Sep 25, 2025 · Last modified: Aug 11, 2026 · CWE-120

EPSS · 30d

40.4%EPSS · 30 days70.7%

2026-08-022026-08-31

KEV catalog record

Product

Cisco / Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense

Vulnerability

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability

Added to KEV

Sep 25, 2025

Remediate by

Sep 26, 2025

Known ransomware use

Summary description

Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a buffer overflow vulnerability that allows for remote code execution. This vulnerability could be chained with CVE-2025-20362.

Required action

The KEV due date refers to the deadline by which FCEB agencies are expected to review and begin implementing the guidance outlined in Emergency Directive (ED) 25-03 (URL listed below in Notes). Agencies must follow the mitigation steps provided by CISA (URL listed below in Notes) and vendor’s instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

Notes

CISA Mitigation Instructions: https://www.cisa.gov/news-events/directives/ed-25-03-identify-and-mitigate-potential-compromise-cisco-devices ; https://www.cisa.gov/news-events/directives/supplemental-direction-ed-25-03-core-dump-and-hunt-instructions ; https://www.cisa.gov/eviction-strategies-tool/create-from-template ; https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks ; https://sec.cloudapps.cisco.com/security/center/private/resources/asa_ftd_continued_attacks#Details ; https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-z5xP8EUB ; https://nvd.nist.gov/vuln/detail/CVE-2025-20333

Technical description

A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker with valid VPN user credentials could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as root, possibly resulting in the complete compromise of the affected device.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-8254210.0 CRI

48.4%

——15A weakness has been identified in Tenda HG10 300001138. Affected by this issue is the function formIPv6Routing of the file /boaform/admin/formIPv6Routing of the component Boa Web Server. This manipulation of the argument destNet causes buffer overflow. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks.1d CVE-2026-824796.3 MED

16.7%

——5A vulnerability was identified in NASA cFS up to 7.0.1. Impacted is the function OS_read of the file modules/protocol/tcp/fsw/src/sbn_tcp_if.c of the component SBN TCP Module. Such manipulation of the argument MsgSz leads to buffer overflow. The attack must be carried out from within the local network. The vendor was contacted early about this disclosure but did not respond in any way.1d CVE-2026-823436.1 MED

1.8%

——1A flaw was found in the file-psd plugin in GIMP. When processing a specially crafted PSD image file, the plugin does not properly validate the channel-count parameter. This incorrect validation leads to improper memory bounds checking, resulting in both a heap out-of-bounds read and a stack out-of-bounds access. This issue can result in an application crash, leading to a denial of service or a limited information disclosure of memory contents.3d CVE-2026-751247.5 HIG

39.8%

——12PLANET GS-4210-16P2S firmware before 3.441b260626 contains a pre-authentication memory corruption vulnerability in the web management interface where the _readHttpParam function copies an oversized HTTP query string without guaranteeing NUL termination, allowing parse_query_string to process attacker-controlled data into a fixed-size stack buffer. An unauthenticated remote attacker can send an oversized GET request to dispatcher.cgi to cause denial of service of the web management interface and potentially trigger memory corruption.3d CVE-2026-801867.6 HIG

33.7%

——10A stack-based buffer overflow vulnerability exists in BlueZ, the Linux Bluetooth protocol stack. A remote user within Bluetooth radio range can send a specially crafted Extended Inquiry Response (EIR) packet that causes a buffer overflow when the target device performs Bluetooth discovery. This vulnerability can lead to a Denial of Service (DoS) by crashing the bluetoothd service and may allow for arbitrary code execution.3d CVE-2026-647055.5 MED

1.7%

——1A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7. An app may be able to cause unexpected system termination or write kernel memory.4d