VulnerabilityPublished 16 Jan 2026

CVE-2026-0613: TheLibrarian.io · Exposure of Sensitive System Information to an Unauthorized Control Sphere

Affects TheLibrarian.ioSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within 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 16 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 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
TheLibrarianTheLibrarian.io	Affected <=1.0	Fixed in–

AI-suggested

Immediately apply the vendor-provided patches for TheLibrarian.io to all affected versions to remediate the vulnerability.
Restrict TheLibrarian's ability to make outbound requests to internal IP ranges by implementing network segmentation and egress filtering at the firewall or cloud security group level.
Monitor and log all outbound requests made by TheLibrarian, especially those targeting internal IP addresses or unusual ports, to detect potential exploitation attempts.
Employ Web Application Firewalls (WAFs) or Intrusion Detection/Prevention Systems (IDS/IPS) to identify and block SSRF-like request patterns.
Conduct regular internal network scans and penetration tests to identify and remediate any exposed internal services that could be discovered via SSRF.
Limit the exposure of sensitive internal services by enforcing strict access controls and minimizing unnecessary service availability within the internal network.
Educate security teams about SSRF risks and ensure incident response plans include procedures for handling SSRF-related incidents.

Description

CVE-2026-0613 is a high-severity vulnerability in TheLibrarian.io that allows unauthorized internal port scanning via SSRF-like behavior through its web_fetch tool. This flaw exposes sensitive system information by enabling attackers to perform GET requests to internal IP addresses and services within the Hetzner cloud environment used by TheLibrarian. The vulnerability does not require authentication or user interaction and can be exploited remotely over the network. Although no known exploits are currently in the wild, the vendor has released patches for all affected versions. European organizations using TheLibrarian.io, especially those hosted on Hetzner infrastructure, are at risk of internal network reconnaissance that could facilitate further attacks. Mitigation involves promptly applying vendor patches, restricting internal service exposure, and monitoring for unusual internal request patterns. Countries with significant Hetzner data center presence and TheLibrarian adoption, such as Germany and the Netherlands, are most likely to be affected.

Impact

For European organizations, especially those using TheLibrarian.io hosted on Hetzner cloud infrastructure, this vulnerability poses a significant risk of internal network reconnaissance by unauthorized actors. Exposure of internal IP addresses and services can lead to the disclosure of sensitive system information, which attackers can leverage to identify vulnerable internal services and plan further attacks such as privilege escalation, data exfiltration, or service disruption. The confidentiality of internal network architecture and service availability information is compromised, potentially undermining trust and compliance with data protection regulations such as GDPR. Organizations relying on TheLibrarian.io for critical document management may face increased risk of targeted attacks if internal network details are exposed. The vulnerability's ease of exploitation without authentication or user interaction further amplifies its threat to European enterprises, particularly those with sensitive or regulated data hosted in Hetzner data centers.

Summary

CVE-2026-0613 is a vulnerability categorized under CWE-497 (Exposure of Sensitive System Information to an Unauthorized Control Sphere) found in TheLibrarian.io, a product used for document and knowledge management. The flaw arises from the 'web_fetch' tool within TheLibrarian, which can be manipulated to perform Server-Side Request Forgery (SSRF)-style GET requests targeting internal IP addresses and services. This behavior effectively enables an attacker to scan internal ports and services within the Hetzner cloud environment where TheLibrarian is hosted. The vulnerability allows an unauthenticated remote attacker to gather sensitive information about internal network topology and running services without requiring user interaction. The CVSS v3.1 score is 7.5 (high), reflecting its network attack vector, low complexity, no privileges required, and no user interaction needed, with a significant impact on confidentiality. While no known exploits have been reported in the wild, the vendor has addressed the issue in all affected versions. The vulnerability's exploitation could serve as a reconnaissance step for more advanced attacks, such as lateral movement or targeted exploitation of internal services. The lack of authentication and user interaction requirements increases the risk of automated scanning and exploitation attempts.

CWE-497Exposure of Sensitive System Information to an Unauthorized Control Sphere (opens in a new tab)
Base weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.
Architecture and Design · Implementation
Production applications should never use methods that generate internal details such as stack traces and error messages unless that information is directly committed to a log that is not viewable by the end user.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V14.3.2 (opens in a new tab)
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
Attack patterns
Web Application Fingerprinting (opens in a new tab)
System Location Discovery (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 Jan 2026, 20:34 UTC

WeaknessesCWE-497

Technical details

References

Community reviews

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