# Critical Telegram Vulnerability Claims Disputed: Researchers Allege No-Click Exploit in Sticker Processing


## The Threat


Security researchers have publicly disclosed claims of a critical vulnerability in Telegram's messaging application that could allow remote attackers to execute arbitrary code on user devices without any user interaction beyond receiving a specially crafted message. The alleged flaw centers on the way Telegram processes corrupted image files embedded within the platform's sticker feature—a functionality used by millions of users daily.


According to the researchers, a malicious actor could craft a message containing a corrupted sticker file and send it to a target user. Upon receipt and automatic processing by the Telegram client, the corrupted sticker allegedly triggers memory corruption or other dangerous behavior within the application, potentially leading to complete device compromise. What makes this claim particularly alarming is the "no-click" nature of the attack—victims would not need to actively open an attachment or click a link; merely receiving the message in their chat history could be sufficient for exploitation.


The vulnerability, if validated, would represent one of the most severe threats to Telegram's 800+ million active users. However, the situation remains contentious: Telegram's leadership has publicly denied that such a vulnerability exists in their platform, creating a high-stakes dispute within the security community about the validity and severity of the claims.


## Severity and Impact


| Attribute | Details |

|-----------|---------|

| CVE Identifier | Pending / Disputed |

| CVSS Score | 9.8 (Critical) |

| CVSS Vector | Network-based, low attack complexity, no authentication required |

| Attack Vector | Network / Messaging Protocol |

| Attack Complexity | Low |

| Authentication | None Required |

| User Interaction | None (no-click exploit) |

| Impact | Complete system compromise possible |

| CWE Classification | CWE-190 (Integer Overflow), CWE-369 (Divide By Zero), or memory corruption variants |


A CVSS score of 9.8 places this vulnerability in the critical category, indicating exceptionally high severity if the claims are substantiated. The "low attack complexity" rating suggests that exploitation would not require specialized knowledge or rare conditions—a reasonably skilled attacker could potentially weaponize this flaw. The absence of authentication requirements and user interaction make this attack surface particularly broad, as any Telegram user globally could theoretically be targeted.


The attack vector appears to involve Telegram's automatic sticker preview and rendering mechanism, which processes image metadata without apparently validating file integrity sufficiently. Corrupted or specially crafted sticker files could trigger integer overflows, buffer overflows, or other memory-safety violations that allow code execution.


## Affected Products


Telegram Clients (across multiple platforms):

  • Telegram Desktop (all versions prior to clarification)
  • Telegram for iOS (affected versions under investigation)
  • Telegram for Android (affected versions under investigation)
  • Telegram Web version (status unclear)

    • Note: Telegram has not officially confirmed which versions, if any, are vulnerable, as the company disputes the vulnerability's existence entirely.


    The vulnerability claims do not appear to affect Telegram's server infrastructure, but rather focus on client-side processing of sticker data, meaning the threat would be device-specific rather than account-wide.


    ## Mitigations


    ### For End Users

  • Update immediately: If Telegram releases a patched version addressing sticker processing, install updates as soon as they become available
  • Disable sticker auto-preview: Users should review Telegram settings to disable automatic sticker preview and rendering if such options are available
  • Monitor for advisories: Follow Telegram's official security announcements and third-party security vendors for confirmation of the vulnerability

    • ### For Organizations

  • Network segmentation: Isolate critical systems from general messaging applications when possible; use separate devices for sensitive work
  • Endpoint security: Deploy advanced endpoint protection tools capable of detecting exploitation attempts and memory corruption attacks
  • Access controls: Limit Telegram access on organizational networks to approved use cases; consider blocking it entirely on security-critical systems
  • Security awareness: Brief staff about the vulnerability claims and advise caution when using messaging platforms for sensitive communications

    • ### For System Administrators

  • Implement strict application whitelisting policies
  • Monitor endpoint processes for suspicious behavior following message receipt
  • Deploy intrusion detection systems capable of identifying exploitation traffic patterns

    • ## References


  • Telegram Official Security Statement: Telegram Security Team's official response and denial (direct statement from Telegram leadership)
  • Researcher Disclosure: Original security research claims and technical analysis
  • CVSS Score Registration: Industry vulnerability database entries (pending official CVE assignment)
  • Security Vendor Analysis: Third-party security firms' assessments of the claimed vulnerability

    • ---


    ### Key Takeaway


    This situation underscores a critical tension in the cybersecurity industry between researchers who identify potential vulnerabilities and vendors who must balance security with maintaining user trust. Until Telegram confirms or provides technical evidence addressing the vulnerability claims, users should remain vigilant about their messaging platform security and consider the potential risks. The 9.8 CVSS score—if accurate—would rank this among the most dangerous Telegram vulnerabilities ever reported. Organizations relying on Telegram for business communications should treat this as a serious threat assessment item until official clarity emerges from Telegram's security team.