# CVE-2025-71253: Unisoc Modem IMS improper input validation remote DoS Source: https://junglewise.ai/threats/cve-2025-71253-unisoc-modem-ims-improper-input-validation-remote-dos Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats Published: 2026-05-06. Updated: 2026-07-25 License: CC BY 4.0 with a link back CVE-2025-71253 · Severity: high · CVSS 7.5 · Published 2026-05-06 A vulnerability exists in the IP Multimedia Subsystem (IMS) of several Unisoc mobile chipsets, which are used to handle voice and data services on smartphones. An attacker could remotely crash the device's modem, leading to a total loss of cellular connectivity and emergency services. This attack can be carried out over the network without any user interaction or special permissions. Technologies: [Unisoc Sc7731e](https://junglewise.ai/threats/technologies/sc7731e), [Unisoc Sc9832e](https://junglewise.ai/threats/technologies/sc9832e), [Unisoc Sc9863a](https://junglewise.ai/threats/technologies/sc9863a), [Unisoc T310](https://junglewise.ai/threats/technologies/t310), [Unisoc T610](https://junglewise.ai/threats/technologies/t610), [Unisoc T618](https://junglewise.ai/threats/technologies/t618), [Unisoc T7200](https://junglewise.ai/threats/technologies/t7200), [Unisoc T7225](https://junglewise.ai/threats/technologies/t7225), [Unisoc T7250](https://junglewise.ai/threats/technologies/t7250), [Unisoc T7255](https://junglewise.ai/threats/technologies/t7255), [Unisoc T7280](https://junglewise.ai/threats/technologies/t7280), [Unisoc T7300](https://junglewise.ai/threats/technologies/t7300), [Unisoc T8100](https://junglewise.ai/threats/technologies/t8100), [Unisoc T8200](https://junglewise.ai/threats/technologies/t8200), [Unisoc T8300](https://junglewise.ai/threats/technologies/t8300), [Unisoc T9100](https://junglewise.ai/threats/technologies/t9100). Vendors: [Unisoc](https://junglewise.ai/threats/vendors/unisoc). ## Quick answers **Is CVE-2025-71253 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-71253 being exploited in the wild. **How severe is CVE-2025-71253?** High severity, with a CVSS score of 7.5, published 6 May 2026. **Which products and versions are affected?** Unisoc Sc7731e Android 13, 14, 15, 16; Unisoc Sc9832e Android 13, 14, 15, 16; Unisoc Sc9863a Android 13, 14, 15, 16; Unisoc T310 Android 13, 14, 15, 16; and 12 more. **Is there a fix for CVE-2025-71253?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it. **How is CVE-2025-71253 attacked?** It is attacked over the network, in device firmware. **Am I affected by CVE-2025-71253?** Check whether you run Unisoc Sc7731e, Unisoc Sc9832e, Unisoc Sc9863a or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you. ## Technical details An improper input validation vulnerability (CWE-20) exists in the Modem IMS component of multiple Unisoc chipsets. The flaw allows a remote, unauthenticated attacker to send malformed packets over the network to trigger a system crash or a denial-of-service (DoS) condition on the modem. The vulnerability affects chipsets running Android versions 13 through 16. Successful exploitation results in the loss of cellular functionality, including voice calls and data, until the modem or device is reset. Unisoc has released a security bulletin detailing the affected chipsets, including the T-series and SC-series models. ## Affected products - Unisoc SC7731E Android 13, 14, 15, 16 - Unisoc SC9832E Android 13, 14, 15, 16 - Unisoc SC9863A Android 13, 14, 15, 16 - Unisoc T310 Android 13, 14, 15, 16 - Unisoc T610 Android 13, 14, 15, 16 - Unisoc T618 Android 13, 14, 15, 16 - Unisoc T7200 Android 13, 14, 15, 16 - Unisoc T7225 Android 13, 14, 15, 16 - Unisoc T7250 Android 13, 14, 15, 16 - Unisoc T7255 Android 13, 14, 15, 16 - Unisoc T7280 Android 13, 14, 15, 16 - Unisoc T7300 Android 13, 14, 15, 16 - Unisoc T8100 Android 13, 14, 15, 16 - Unisoc T9100 Android 13, 14, 15, 16 - Unisoc T8200 Android 13, 14, 15, 16 - Unisoc T8300 Android 13, 14, 15, 16 ## Timeline - 2026-05-05: advisory: Initial advisory published by Unisoc - 2026-05-06: disclosed: NVD publication date ## References - [https://www.unisoc.com/en/support/product-security-bulletin/2051836844671422466](https://www.unisoc.com/en/support/product-security-bulletin/2051836844671422466) ## Related threats - [Unisoc bootloader out-of-bounds write in firmware update](https://junglewise.ai/threats/cve-2026-80335-in-the-bootloader-download-module-there-is-a-possible-out-of) - [Unisoc UFS firmware out-of-bounds write in FFU](https://junglewise.ai/threats/cve-2026-121803-in-ufs-field-firmware-update-ffu-functionality-there-is-a) - [Unisoc NR modem improper input validation in T8000/T9000 series chipsets](https://junglewise.ai/threats/cve-2025-71256-unisoc-nr-modem-improper-input-validation-in-t8000-t9000-series) - [Unisoc Modem IMS improper input validation denial of service](https://junglewise.ai/threats/cve-2025-71255-unisoc-modem-ims-improper-input-validation-denial-of-service) - [Unisoc Modem IMS improper input validation denial of service](https://junglewise.ai/threats/cve-2025-71254-unisoc-modem-ims-improper-input-validation-denial-of-service)