CVE-2025-67720VulnerabilityPublished 11 Dec 2025

CVE-2025-67720: Mayuri-Chan pyrofork · Path Traversal

Affects Mayuri-Chan pyroforkSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium : upgrade to 2.3.69 when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.3.69

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: High
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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 11 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

Upgrade mayuri-chan/pyrofork to 2.3.69.

Affected software

Product	Affected	Fixed in
GitHubmayuri-chan/pyrofork`pkg:github/mayuri-chan/pyrofork`Other threats	Affected <2.3.69	Fixed in 2.3.69

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

AI-suggested

European organizations should immediately upgrade pyrofork to version 2.3.69 or later to apply the official fix. Until upgrade is possible, implement strict input validation and sanitization on filenames derived from Telegram messages, rejecting or neutralizing any path traversal sequences such as '../'. Employ file system access controls and sandboxing to restrict the directories where pyrofork can write files, minimizing potential damage from exploitation. Monitor logs for suspicious file write activities and unexpected file modifications. Consider disabling automatic media downloads or requiring explicit user confirmation before downloading files. Additionally, apply network-level filtering to limit exposure to untrusted Telegram messages where feasible. Conduct security reviews of Telegram bot implementations to ensure they do not blindly trust user-supplied filenames. Finally, maintain awareness of updates and advisories related to pyrofork and Telegram API integrations.

Description

Pyrofork is a modern, asynchronous MTProto API framework. Versions 2.3.68 and earlier do not properly sanitize filenames received from Telegram messages in the download_media method before using them in file path construction. When downloading media, if the user does not specify a custom filename (which is the common/default usage), the method falls back to using the file_name attribute from the media object. The attribute originates from Telegram's DocumentAttributeFilename and is controlled by the message sender. This issue is fixed in version 2.3.69.

Impact

For European organizations, the primary impact of this vulnerability is on the integrity of systems running vulnerable pyrofork versions. Attackers can overwrite or modify arbitrary files by sending specially crafted Telegram messages, potentially leading to unauthorized code execution, configuration corruption, or disruption of application functionality. While confidentiality and availability are not directly impacted, the integrity compromise could facilitate further attacks or data loss. Organizations relying on Telegram-based automation, bots, or media processing pipelines using pyrofork are at risk. The vulnerability could be exploited to implant malicious files or disrupt critical services, especially in sectors like finance, government, or critical infrastructure where Telegram is used for communication or automation. The requirement for user interaction (receiving a malicious message) limits mass exploitation but targeted attacks remain a concern. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as the vulnerability is publicly disclosed.

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (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 18 Dec 2025, 05:01 UTC

WeaknessesCWE-22

Technical details

References

Community reviews

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