CVE-2025-8836VulnerabilityPublished 11 Aug 2025Updated 12 Aug 2025

CVE-2025-8836: JasPer · Reachable Assertion

Affects JasPerSource CVE Database V5

Not known to be exploited · CVSS 4.8 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

4.8Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
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: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
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 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

Affected software

Product	Affected	Fixed in
JasPer	Affected =4.2.0 =4.2.1 =4.2.2 =4.2.3 =4.2.4 =4.2.5	Fixed in–

AI-suggested

European organizations should prioritize patching affected JasPer versions by applying the official patch identified by commit 79185d32d7a444abae441935b20ae4676b3513d4 or upgrading to a fixed version beyond 4.2.5. Since the vulnerability requires local access, organizations should enforce strict access controls and limit local user privileges to trusted personnel only. Implementing application whitelisting and monitoring for abnormal termination of image processing applications can help detect exploitation attempts. For environments where JasPer is embedded in third-party software, coordinate with vendors to ensure timely updates. Additionally, conduct audits to identify all systems using JasPer and verify version levels. Employ host-based intrusion detection systems (HIDS) to monitor for suspicious local activity related to image encoding processes. Finally, educate system administrators and users about the risks of local exploitation and the importance of applying patches promptly.

Description

A vulnerability was determined in JasPer up to 4.2.5. Affected by this issue is the function jpc_floorlog2 of the file src/libjasper/jpc/jpc_enc.c of the component JPEG2000 Encoder. The manipulation leads to reachable assertion. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used. The patch is identified as 79185d32d7a444abae441935b20ae4676b3513d4. It is recommended to apply a patch to fix this issue.

Impact

For European organizations, the primary impact of CVE-2025-8836 is the potential for local denial of service on systems utilizing the vulnerable JasPer versions for JPEG-2000 image encoding. This could disrupt services or applications that rely on image processing, particularly in sectors such as digital media, publishing, healthcare imaging, and geospatial analysis where JPEG-2000 is more commonly used. Since exploitation requires local access, the threat is more relevant in environments where untrusted users have local system access or where multi-user systems are in place. The vulnerability does not allow remote code execution or data compromise, limiting its impact on confidentiality and integrity. However, denial of service could affect availability of critical image processing workflows, potentially delaying operations or causing system instability. Organizations with automated image processing pipelines or embedded systems using JasPer should be particularly vigilant. Given the public disclosure of the exploit, there is a risk of increased attempts to leverage this vulnerability in targeted attacks or insider threat scenarios.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 19 Aug 2025, 01:47 UTC

Technical details

References

Community reviews

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