CVE-2025-13803VulnerabilityPublished 1 Dec 2025

CVE-2025-13803: MediaCrush · Improper Neutralization of HTTP Headers for Scripting Syntax

Affects MediaCrushSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% 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:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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: 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 Vulnerable System.
Vulnerable system 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 to 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.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Dec 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
PyPImediacrush`pkg:pypi/mediacrush`Other threats	Affected =1.0.0 =1.0.1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should immediately assess their use of MediaCrush versions 1.0.0 and 1.0.1 and plan to upgrade to patched versions once available. In the absence of official patches, implement strict input validation and sanitization on HTTP headers, especially the Host header, to neutralize scripting syntax and prevent injection. Deploy web application firewalls (WAFs) with custom rules to detect and block suspicious header manipulations. Monitor HTTP traffic logs for anomalous header values indicative of exploitation attempts. Restrict network exposure of MediaCrush instances to trusted networks or VPNs to reduce attack surface. Conduct security testing focused on header injection vectors to identify and remediate weaknesses. Maintain up-to-date threat intelligence feeds to detect emerging exploits related to this CVE. Finally, ensure incident response plans include scenarios for header injection attacks to enable rapid containment and recovery.

Description

A vulnerability was identified in MediaCrush 1.0.0/1.0.1. The affected element is an unknown function of the file /mediacrush/paths.py of the component Header Handler. Such manipulation of the argument Host leads to improper neutralization of http headers for scripting syntax. The attack can be launched remotely.

Impact

For European organizations, exploitation of this vulnerability could lead to unauthorized manipulation of HTTP headers, potentially enabling attacks such as cross-site scripting, session hijacking, or cache poisoning. This could compromise the confidentiality of user data, integrity of communications, and availability of services relying on MediaCrush. MediaCrush is often used for media hosting and streaming, so disruption or compromise could affect content delivery platforms, media companies, and any enterprise relying on this software for digital asset management. Given the remote exploitability without authentication, attackers could target exposed MediaCrush instances to gain footholds or disrupt services. The impact is particularly significant for organizations handling sensitive media content or personal data under GDPR regulations, as breaches could lead to regulatory penalties and reputational damage.

References

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