weebzone Telegram-Stremio up to 5.1.0 stream_handler encode_string/decode_string msg_id improper authorization

Summaryinfo

A vulnerability identified as problematic has been detected in weebzone Telegram-Stremio up to 5.1.0. This issue affects the function encode_string/decode_string of the component stream_handler. This manipulation of the argument msg_id causes improper authorization. This vulnerability appears as CVE-2026-109427. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic was found in weebzone Telegram-Stremio up to 5.1.0. Affected by this vulnerability is the function encode_string/decode_string of the component stream_handler. The manipulation of the argument msg_id with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality. The summary by CVE is:

Telegram-Stremio through 5.1.0 contains a broken object-level authorization vulnerability that allows authenticated token holders to access arbitrary chat messages by forging unsigned, unauthenticated stream IDs decoded via encode_string/decode_string functions. Attackers can craft or enumerate sequential msg_id values and set a global flag in the stream_handler endpoint to route requests through the operator's personal Userbot account, exposing private channels, groups, and Saved Messages, while the unauthenticated thumb_handler endpoint further discloses thumbnails from those same chats without any token validation.

It is possible to read the advisory at gist.github.com. This vulnerability is known as CVE-2026-109427 since 10/12/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/12/2026). The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• weebzone

Name

• Telegram-Stremio

Version

• 5.0
• 5.1.0

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CPE 2.2info

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