CVE-2025-55151VulnerabilityPublished 11 Aug 2025

CVE-2025-55151: Stirling-PDF · Server-Side Request Forgery (SSRF)

Affects Stirling-PDFSource CVE Database V5

Not known to be exploited · CVSS 8.6 High : upgrade to 1.1.0 soon.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

8.6High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.1.0

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

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

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: 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: 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 impacted component 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 impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Aug 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 2026-10-25.

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

Upgrade Stirling-PDF to 1.1.0.

Affected software

Product	Affected	Fixed in
Stirling-Tools Stirling-PDF	Affected <1.1.0	Fixed in 1.1.0

AI-suggested

European organizations should implement the following specific mitigation measures: 1) Immediately upgrade Stirling-PDF installations to version 1.1.0 or later, where the SSRF vulnerability has been patched. 2) Restrict network access to the Stirling-PDF service, ensuring it is not exposed to untrusted networks or the public internet. 3) Implement strict egress filtering on servers running Stirling-PDF to prevent unauthorized outbound requests, limiting the ability of SSRF attacks to reach internal or external targets. 4) Employ application-layer firewall rules or web application firewalls (WAFs) to detect and block suspicious request patterns targeting the /api/v1/convert/file/pdf endpoint. 5) Conduct internal audits to identify any instances of Stirling-PDF in use, including shadow IT deployments, to ensure all are updated or isolated. 6) Monitor logs for unusual outbound requests or access patterns indicative of SSRF exploitation attempts. 7) Consider network segmentation to isolate document processing servers from sensitive internal resources. 8) Educate development and IT teams about SSRF risks and secure coding practices to prevent similar vulnerabilities in custom integrations.

Description

Stirling-PDF is a locally hosted web application that performs various operations on PDF files. Prior to version 1.1.0, the "convert file to pdf" functionality (/api/v1/convert/file/pdf) uses LibreOffice's unoconvert tool for conversion, and SSRF vulnerabilities exist during the conversion process. This issue has been patched in version 1.1.0.

Impact

For European organizations, the SSRF vulnerability in Stirling-PDF poses significant risks, especially for entities relying on this tool for document processing within internal networks. Exploitation could allow attackers to access internal services, including databases, administrative interfaces, or cloud metadata services, potentially leading to data breaches or lateral movement within the network. Confidentiality of sensitive documents and internal infrastructure information is at risk. Given the vulnerability requires no authentication or user interaction, attackers can remotely exploit exposed instances, increasing the threat surface. Organizations in sectors such as finance, healthcare, government, and critical infrastructure, which often handle sensitive documents and may deploy such tools internally, face heightened risk. Additionally, the use of LibreOffice's unoconvert tool as part of the conversion process means that any misconfiguration or exposure of Stirling-PDF to untrusted networks could exacerbate the impact. The lack of known exploits in the wild provides a window for proactive mitigation, but the high CVSS score and ease of exploitation necessitate urgent patching and network controls.

CWE-918Server-Side Request Forgery (SSRF) (opens in a new tab)
Base weaknessCWE Top 25 (2025): #22OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.6.1 (opens in a new tab)
V5.2.6 (opens in a new tab)
Attack patterns
Server Side Request Forgery (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 19 Aug 2025, 01:44 UTC

WeaknessesCWE-918

Technical details

References

Community reviews

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