# CVE-2025-71251: Unisoc Modem improper input validation in IMS

Source: https://junglewise.ai/threats/cve-2025-71251-unisoc-modem-improper-input-validation-in-ims  
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-2025-71251 · Severity: high · CVSS 7.5 · Published 2026-05-06

A vulnerability exists in the modem software of several Unisoc chipsets used in mobile devices. This component handles IP Multimedia Subsystem (IMS) functions, which are responsible for delivering multimedia services like Voice over LTE (VoLTE). An attacker could remotely trigger a system crash, leading to a total loss of cellular connectivity and service availability for the user.

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-2025-71251 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-71251 being exploited in the wild.

**How severe is CVE-2025-71251?** 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-2025-71251?** 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-2025-71251 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2025-71251?** 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

A vulnerability classified as improper input validation (CWE-20) exists in the Unisoc Modem IMS (IP Multimedia Subsystem) component. The flaw allows a remote, unauthenticated attacker to send specially crafted network traffic that triggers a system crash. This results in a denial of service (DoS) affecting the device's cellular and multimedia communication capabilities. The vulnerability affects multiple chipsets running Android versions 13 through 16. No additional execution privileges or user interaction are required for exploitation.

## 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 T8200 Android 13, 14, 15, 16
- Unisoc T8300 Android 13, 14, 15, 16
- Unisoc T9100 Android 13, 14, 15, 16

## Timeline

- 2026-05-06: advisory: Initial advisory published by Unisoc
- 2026-05-06: disclosed: CVE published to NVD

## 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)