VulnerabilityPublished 29 Jan 2026Updated 10 Feb 2026

CVE-2026-25061: simsong tcpflow · Out-of-bounds Write

Affects simsong tcpflowSource CVE Database V5

Public exploit available · CVSS 5.5 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 4.0 base score

5.5Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, 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
simsongtcpflow	Affected <=1.61	Fixed in–
GitHubsimsong/tcpflow`pkg:github/simsong/tcpflow`Other threats	Affected <=1.61	Fixed in–

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

AI-suggested

Since no official patches are available, European organizations should implement the following specific mitigations: 1) Limit tcpflow exposure by restricting access to trusted wireless networks and filtering out untrusted or suspicious 802.11 management frames at network boundaries or wireless access points. 2) Deploy network intrusion detection systems (NIDS) capable of detecting anomalous or malformed 802.11 management frames indicative of exploitation attempts. 3) Run tcpflow with the least privileges possible and consider isolating it within containerized or sandboxed environments to reduce impact of potential crashes or exploitation. 4) Monitor tcpflow logs and system stability closely for signs of crashes or unusual behavior. 5) Engage with the tcpflow community or vendor to track patch releases and apply updates promptly once available. 6) As a temporary workaround, consider disabling wireless frame parsing features if feasible or replacing tcpflow with alternative tools not affected by this vulnerability. 7) Conduct regular security assessments of wireless infrastructure to identify and mitigate other potential attack vectors.

Description

tcpflow is a TCP/IP packet demultiplexer. In versions up to and including 1.61, wifipcap parses 802.11 management frame elements and performs a length check on the wrong field when handling the TIM element. A crafted frame with a large TIM length can cause a 1-byte out-of-bounds write past `tim.bitmap[251]`. The overflow is small and DoS is the likely impact; code execution is potential, but still up in the air. The affected structure is stack-allocated in `handle_beacon()` and related handlers. As of time of publication, no known patches are available.

Impact

For European organizations, the primary impact of CVE-2026-25061 is the potential for denial of service on systems running vulnerable tcpflow versions, which could disrupt network traffic analysis and monitoring activities. This may affect incident response teams, network security monitoring, and forensic investigations relying on tcpflow data. Although code execution is not confirmed, if exploited, it could lead to further compromise of monitoring infrastructure, potentially allowing attackers to manipulate captured data or gain footholds in internal networks. Organizations involved in wireless network management, telecom operators, research institutions, and critical infrastructure sectors that utilize tcpflow for packet analysis are at higher risk. Disruptions could impact operational continuity and security visibility. The lack of available patches increases exposure duration, necessitating immediate mitigation efforts. Additionally, attackers could leverage this vulnerability to evade detection by causing tcpflow to crash or behave unpredictably.

CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
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)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Feb 2026, 11:52 UTC

WeaknessesCWE-787

Technical details

References

Community reviews

Related threats