Cyber Resilience

CVE-2025-20359

Memory Safety

Memory Safety
Published
15 October 2025
Modified
15 April 2026
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
EPSS Score 0.0039 32th percentile
Risk Priority 51 floored blend · peak EPSS

Summary

CVE-2025-20359 is a medium-severity Buffer Under-read (CWE-127) vulnerability in Cisco (inferred from references). Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 32th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to RA-5 (Vulnerability Monitoring and Scanning) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Multiple Cisco products are affected by a vulnerability in the Snort 3 HTTP Decoder that could allow an unauthenticated, remote attacker to cause the disclosure of possible sensitive data or cause the Snort 3 Detection Engine to crash. This vulnerability…

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is due to an error in the logic of buffer handling when the MIME fields of the HTTP header are parsed. This can result in a buffer under-read. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to induce one of two possible outcomes: the unexpected restarting of the Snort 3 Detection Engine, which could cause a denial of service (DoS) condition, or information disclosure of sensitive information in the Snort 3 data stream. Due to the under-read condition, it is possible that sensitive information that is not valid connection data could be returned.

CWE(s)
CWE-127

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-5928Shared CWE-127
CVE-2025-32050Shared CWE-127
CVE-2024-10395Shared CWE-127
CVE-2024-25629Shared CWE-127
CVE-2026-45683Shared CWE-127

Affected Assets

Cisco
—
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

RA-5 Vulnerability Monitoring and Scanning good match

Vulnerability scanning can locate known buffer-under-read instances in deployed code.

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (static analysis, fuzzing, bounds checkers) directly finds buffer under-read flaws before deployment.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles require bounds-checked memory accesses and safe pointer arithmetic that structurally stop buffer under-reads from being introduced.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and static analysis directly prevent introduction of buffer under-reads.

ID.RA-01 partial match
prevents

Vulnerability scanning can discover buffer under-read flaws so they can be recorded and fixed.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software removes known instances of buffer under-read.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect buffer under-reads before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and bounds checking that can prevent buffer under-reads.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify safe buffer handling and bounds checking.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include memory-safety and bounds-checking mechanisms.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require bounds checking and safe pointer arithmetic.

References