Vendor

Calif

2 mentions in 7 days · 3 in 30 days · 3 total · first seen Sep 8, 2026 · last 6d ago

Timeline3 articles

Researchers Build WeChat Zero-Click Worm Hijacking Phones via Calls

Calif researchers built WeWorm, a zero-click worm exploiting a WeChat VoIP memory-corruption RCE that Tencent has now patched.

Calif researchers found a memory corruption flaw in WeChat's VoIP stack in July using LLM-assisted analysis and built working exploits within two days, then integrated them into WeWorm, which they call the first zero-click worm spreading through WeChat calls on iOS and Android. A crafted incoming call yields remote code execution with no user interaction, giving full control of the victim's WeChat account; the attacker only needs to be on the victim's friend list, easily achieved by compromising a contact first. Tencent confirmed the bug and shipped patches in WeChat Android 8.0.77 and iOS 8.0.76, and chaining with other OS bugs could yield full device control.

Infosecurity Magazineupdated Sep 10, 00:56 UTC · 5d agofirst Sep 9, 15:00 UTC · 6d agoExploit / PoC 3 sources

WeChat worm could pwn a friend before they even answered the call

Calif researchers demoed WeWorm, a zero-click WeChat VoIP memory-corruption worm enabling account takeover; Tencent patched it August 21.

Security firm Calif found a memory corruption bug in WeChat's VoIP stack that let a trusted contact take over a user's account simply by calling them, without the call being answered. The demo worm then called the victim's contacts to self-propagate across iOS and Android; declining the call prevented infection. Tencent pushed fixes on August 21, and Calif said chaining the bug with other Android and iOS flaws could yield full device control. Calif used AI to find the vulnerability and build its first RCE exploit in about two days.

The Register · Securityupdated Sep 10, 00:56 UTC · 5d agofirst Sep 9, 12:45 UTC · 6d agoExploit / PoC 3 sources

WeWorm – First 0-Click Worm Spreading Through WeChat Calls Across iOS and Android

Researchers demonstrated WeWorm, a zero-click worm exploiting a memory-corruption flaw in WeChat's VoIP stack to spread via calls across iOS and Android.

Security firm Calif published WeWorm, a proof-of-concept zero-click worm exploiting a memory-corruption bug in WeChat's VoIP stack to spread through voice calls on iOS and Android without the victim answering. The demo chained a Pixel 10a, an iPhone 17e, and a second Pixel 10a, compromising each device while the call was still ringing and giving full control of the WeChat account. The attacker must already be on the victim's friend list, but compromised contacts become the propagation layer across a platform with over 1.4 billion monthly users. Calif reported the bug to Tencent in July 2026, and Tencent has since mitigated it; full technical details are withheld for a later conference presentation.

Cyber Security NewsSep 8, 12:09 UTC · 7d agoExploit / PoC

Appears with

vendor Tencent 3 product WeChat 3 organization Tencent 2 malware WeWorm 2 organization Calif 2 product WeWorm 2 product Android 1 product Weixin 1 organization Georgetown University 1 product iOS 1

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