VulnerabilityPublished 31 Dec 2025Updated 2 Jan 2026

CVE-2025-11961: The Tcpdump Group libpcap · Buffer Over-read

Affects The Tcpdump Group libpcapSource CVE Database V5

Not known to be exploited · CVSS 1.9 Low.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

1.9Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Local
Attack Complexity: High
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 31 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubthe-tcpdump-group/libpcap`pkg:github/the-tcpdump-group/libpcap`Other threats	Affected =0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2025-11961, European organizations should implement several specific measures beyond generic advice: 1) Audit and update all software components and tools that depend on libpcap to ensure they handle MAC address inputs robustly, applying any vendor patches promptly once available. 2) Implement strict input validation and sanitization for MAC address strings before passing them to pcap_ether_aton() or related functions, rejecting malformed or unexpected formats. 3) Limit the use of pcap_ether_aton() to trusted inputs and contexts, avoiding processing untrusted or user-supplied data without validation. 4) Restrict local high-privilege access to systems running libpcap-dependent applications, enforcing least privilege and strong authentication controls to reduce exploitation risk. 5) Monitor application logs and system behavior for anomalies indicative of memory corruption or crashes related to network capture tools. 6) Consider deploying runtime protections such as Address Space Layout Randomization (ASLR) and stack canaries to mitigate exploitation impact. 7) Engage with software vendors and open-source communities to track patch releases and vulnerability disclosures related to libpcap. 8) Conduct regular security assessments and code reviews focusing on input handling in network capture utilities.

Description

pcap_ether_aton() is an auxiliary function in libpcap, it takes a string argument and returns a fixed-size allocated buffer. The string argument must be a well-formed MAC-48 address in one of the supported formats, but this requirement has been poorly documented. If an application calls the function with an argument that deviates from the expected format, the function can read data beyond the end of the provided string and write data beyond the end of the allocated buffer.

Impact

For European organizations, the impact of CVE-2025-11961 is generally low but not negligible. Since exploitation requires local high-privilege access, remote attackers cannot easily leverage this vulnerability. However, insider threats or compromised privileged accounts could exploit malformed MAC address inputs to cause memory corruption in applications using libpcap, potentially leading to application crashes or integrity issues. This could disrupt network monitoring or security operations, affecting incident detection and response capabilities. Critical infrastructure sectors such as telecommunications, finance, and energy that rely heavily on network analysis tools incorporating libpcap might experience operational disruptions if this vulnerability is exploited. Although confidentiality and availability impacts are minimal, the integrity of captured network data or the stability of monitoring tools could be compromised, reducing trust in security telemetry. The absence of known exploits and patches reduces immediate risk but underscores the need for vigilance and proactive mitigation in sensitive environments.

CWE-126Buffer Over-read (opens in a new tab)
Variant weakness
The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-122Heap-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #16
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Pre-design: Use a language or compiler that performs automatic bounds checking.
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/the-tcpdump-group/libpcap/commit/b2d2f9a9a0581c40780bde509f7cc715920f1c02 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Jan 2026, 03:26 UTC

WeaknessesCWE-126, CWE-122

Technical details

References

Community reviews

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