VulnerabilityPublished 15 Sep 2025

CVE-2025-57248: SumatraPDF · NULL Pointer Dereference

Source CVE Database V5

Not known to be exploited · CVSS 7.3 High.

Data as of 26 Oct 2026, 16:39 UTC

CVSS 3.1 base score

7.3High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% 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:L/I:L/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to 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: 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 15 Sep 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

AI-suggested

European organizations should immediately audit their use of SumatraPDF, particularly version 3.5.2, and identify systems where .djvu files are opened or processed. Until a patch is available, organizations should consider the following mitigations: 1) Disable or restrict the opening of .djvu files in SumatraPDF or replace SumatraPDF with alternative document viewers that do not exhibit this vulnerability. 2) Implement file type filtering at email gateways and endpoint security solutions to block or quarantine suspicious .djvu files from untrusted sources. 3) Educate users about the risks of opening unsolicited or unknown .djvu files, especially from external or unverified senders. 4) Monitor application crash logs and system events for signs of exploitation attempts or abnormal behavior related to SumatraPDF. 5) If SumatraPDF is embedded in automated workflows, temporarily suspend processing of .djvu files or switch to safer processing tools. 6) Stay alert for official patches or updates from SumatraPDF developers and apply them promptly once available. 7) Consider sandboxing or isolating document viewers to limit the impact of crashes or potential exploitation.

Description

A null pointer dereference vulnerability was discovered in SumatraPDF 3.5.2 during the processing of a crafted .djvu file. When the file is opened, the application crashes inside libmupdf.dll, specifically in the DataPool::has_data() function.

Impact

For European organizations, the primary impact of this vulnerability is the potential for denial-of-service attacks against users or systems relying on SumatraPDF 3.5.2 for viewing .djvu files. This could disrupt document access in environments where .djvu files are used, such as academic institutions, publishing houses, or archival services that handle scanned documents in this format. While the vulnerability does not currently indicate remote code execution, the forced application crash could be exploited to interrupt workflows or cause operational downtime. Organizations with automated document processing pipelines that include SumatraPDF might experience service interruptions. Additionally, if attackers use crafted .djvu files as part of phishing or social engineering campaigns, unsuspecting users opening such files could trigger crashes, leading to loss of productivity or potential data loss if unsaved work is lost. The lack of a patch or mitigation at the time of disclosure increases the risk window. However, the impact is somewhat limited by the niche usage of the .djvu format and the specific version affected.

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/sumatrapdfreader/sumatrapdf/issues/5035 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 15 Sep 2025, 15:30 UTC

WeaknessesCWE-476

Technical details

References

Community reviews

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