VulnerabilityPublished 28 Jan 2026

CVE-2026-24857: simsong bulk_extractor · Heap-based Buffer Overflow

Affects simsong bulk_extractorSource CVE Database V5

Not known to be exploited · CVSS 5.5 Medium.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 4.0 base score

5.5Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 37% 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 28 Jan 2026
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 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
simsongbulk_extractor	Affected >=1.4 <=2.1.1	Fixed in–

AI-suggested

Until an official patch is released, European organizations should implement strict controls on the sources of disk images processed by bulk_extractor, avoiding untrusted or unknown RAR archives. Employ sandboxing or isolated environments for forensic analysis to contain potential exploitation. Use memory protection tools such as AddressSanitizer or other runtime protections to detect and prevent exploitation during analysis. Monitor bulk_extractor usage logs for anomalies or crashes that could indicate exploitation attempts. Consider alternative forensic tools that do not embed vulnerable unrar code or use updated versions if available. Establish network segmentation and least privilege principles for forensic workstations to limit attacker movement if compromise occurs. Maintain up-to-date threat intelligence to respond quickly once patches or exploits emerge. Engage with the vendor or community for updates and potential workarounds. Finally, conduct regular security training for forensic analysts to recognize suspicious disk images and handle them securely.

Description

CVE-2026-24857 is a medium-severity heap-based buffer overflow vulnerability in the simsong bulk_extractor tool, specifically in its embedded unrar code used for RAR PPM LZ decoding. The flaw exists in versions 1.4 through 2.1.1 and can be triggered by a crafted RAR archive inside a disk image, causing out-of-bounds writes leading to crashes or memory corruption. There is potential for remote code execution (RCE) exploitation, although no known exploits or patches are currently available. The vulnerability requires no authentication or user interaction and can be exploited remotely by processing malicious disk images. European organizations using bulk_extractor for digital forensics or incident response may face risks of system crashes or compromise. Mitigation currently relies on avoiding untrusted RAR files and monitoring for updates from the vendor. Countries with significant digital forensics operations and cybersecurity industries, such as Germany, the UK, France, and the Netherlands, are more likely to be affected due to their adoption of such tools.

Impact

For European organizations, the vulnerability poses a risk of denial-of-service through crashes or potentially full system compromise via remote code execution when processing malicious disk images containing crafted RAR archives. This can disrupt forensic investigations, delay incident response, and compromise the integrity and confidentiality of forensic data. Organizations involved in law enforcement, cybersecurity firms, and governmental agencies conducting digital forensics are especially at risk. The exploitation could allow attackers to gain unauthorized access to forensic workstations, manipulate evidence, or pivot within networks. The absence of patches increases exposure time, and reliance on bulk_extractor in critical investigations amplifies operational risks. Additionally, memory corruption vulnerabilities can be leveraged to bypass security controls, increasing the threat to system integrity. The medium CVSS score indicates moderate risk, but the potential for RCE elevates the impact if exploited successfully.

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/simsong/bulk_extractor/security/advisories/GHSA-rh8m-9xrx-q64q (opens in a new tab)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Feb 2026, 08:54 UTC

WeaknessesCWE-122

Technical details

References

Community reviews

Related threats