# CVE-2025-71255: Unisoc Modem IMS improper input validation denial of service

Source: https://junglewise.ai/threats/cve-2025-71255-unisoc-modem-ims-improper-input-validation-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-06. Updated: 2026-07-20  
License: CC BY 4.0 with a link back

CVE-2025-71255 · 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 modern voice and data communication. An attacker could remotely crash the modem, causing a complete loss of cellular connectivity and emergency services without any user interaction.

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-2025-71255 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-71255 being exploited in the wild.

**How severe is CVE-2025-71255?** 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-2025-71255?** 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-2025-71255 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2025-71255?** 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

The vulnerability is classified as CWE-20 (Improper Input Validation) within the Modem IMS (IP Multimedia Subsystem) component of various Unisoc chipsets. The flaw allows a remote attacker to send specially crafted network traffic that the modem fails to validate correctly, leading to a system crash. This results in a Denial of Service (DoS) condition affecting cellular services. The attack vector is network-based, requires no authentication (PR:N), and no user interaction (UI:N). Affected chipsets include a wide range of Unisoc models (SC and T series) running Android versions 13 through 16.

## 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/T618 Android 13, 14, 15, 16
- Unisoc T7200/T7225/T7250/T7255/T7280/T7300 Android 13, 14, 15, 16
- Unisoc T8100/T8200/T8300/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)

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- [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-2025-71254-unisoc-modem-ims-improper-input-validation-denial-of-service)
- [Unisoc Modem IMS improper input validation remote DoS](https://junglewise.ai/threats/cve-2025-71253-unisoc-modem-ims-improper-input-validation-remote-dos)