CVE-2026-25291

Executive Summary

CVE-2026-25291 is a memory corruption vulnerability in Qualcomm Sar1165P firmware caused by improper synchronization when concurrent operations are performed on shared memory page lists. An attacker with local low-privileged access can trigger a use-after-free condition (CWE-416), potentially leading to arbitrary code execution, privilege escalation, or denial of service within the affected firmware context. The vulnerability carries a CVSS score of 7.8 (High) and, as of this report, has no public proof-of-concept, exploit code, or active exploitation observed in the wild.

Technical Analysis

The vulnerability resides in the memory management subsystem of Qualcomm Sar1165P firmware. According to the NVD description, the flaw is rooted in the absence of proper synchronization mechanisms when concurrent operations occur on shared memory page lists. This is a classic concurrency-induced memory corruption issue.

In embedded firmware and kernel-level environments, shared memory page lists are data structures that track physical or virtual memory pages for allocation, deallocation, or remapping. When multiple execution contexts (e.g., interrupt handlers, threads, or different CPU cores) access and modify the same page list without adequate locking or atomic operations, a race condition occurs. The window of vulnerability allows one context to free a page or remove it from the list while another context still holds a reference to that page or is in the process of updating the list.

This results in a use-after-free (CWE-416) condition: a dangling pointer remains in the list or in a local variable, and subsequent access to that freed memory can lead to memory corruption, data leakage, or execution flow hijacking. The CVSS vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) indicates that the attack requires local access, low privileges, and no user interaction, with high impact on confidentiality, integrity, and availability.

The exact function names, code paths, or memory management components involved are not disclosed in the available description. The vulnerability class is well-understood in kernel and firmware development, where synchronization primitives such as spinlocks, mutexes, or atomic operations are critical. The lack of proper synchronization in the Sar1165P firmware's memory management code suggests a design or implementation oversight that could be exploited by a local attacker.

The attack surface is the local device environment. An attacker must already have a foothold on the system with low privileges, such as a malicious application or a compromised process. The vulnerable firmware runs at a privileged level, so successful exploitation could allow the attacker to elevate privileges, execute arbitrary code in the firmware context, or cause a system crash.

Exploitation Scenarios

No public proof-of-concept or exploit code is available for CVE-2026-25291. The following exploitation scenario is inferred from the vulnerability class (use-after-free via race condition) and the CVSS vector.

1. Reconnaissance/target identification: The attacker identifies a target device running Qualcomm Sar1165P firmware. This could be a smartphone, tablet, IoT device, or automotive component. The attacker gains initial local access with low privileges, either through a malicious app installed by the user, a compromised process, or a separate vulnerability.

2. Triggering the race condition: The attacker executes a process or thread that performs operations on the shared memory page lists concurrently with a legitimate system operation. By timing the operations, the attacker attempts to cause a use-after-free condition. For example, the attacker might allocate and free memory pages while the firmware is performing memory management tasks, exploiting the lack of synchronization.

3. Payload/execution: Once the use-after-free is triggered, the attacker can attempt to control the freed memory region. This might involve heap grooming or spraying to place controlled data in the freed page. When the firmware accesses the dangling pointer, it could dereference attacker-controlled data, leading to arbitrary code execution or privilege escalation. The attacker may also use the corruption to bypass security checks or modify kernel structures.

4. Post-exploitation impact: Successful exploitation allows the attacker to execute code with the privileges of the firmware (likely kernel or secure world). This could enable persistent backdoor installation, data exfiltration, disabling security features, or further lateral movement within the device. The high confidentiality, integrity, and availability impacts reflect the severity of a kernel-level compromise.

It is important to note that no public exploit exists, and the attack chain described is based on the general exploitation pattern for race-condition-based use-after-free vulnerabilities. The actual exploitation may require deep knowledge of the specific firmware and memory layout.

Impact Assessment

The business impact of CVE-2026-25291 is significant for organizations and users relying on devices with Qualcomm Sar1165P firmware. The CVSS score of 7.8 (High) reflects the potential for complete compromise of the affected component. The vector indicates local access with low privileges, meaning a malicious app or a compromised process can escalate to firmware-level privileges. This could lead to persistent compromise, data theft, and device takeover.

Affected systems include any device using the Sar1165P chipset, which may span mobile devices, automotive systems, and IoT products. The blast radius depends on the deployment context; in enterprise environments, managed mobile devices or embedded systems could be at risk. Since the vulnerability is in firmware, patching may require vendor-specific updates, and the lack of a publicly confirmed patch increases risk.

The EPSS score is 0.00110 (1.2% percentile), indicating a very low probability of exploitation in the wild within the next 30 days. CISA KEV does not list this CVE, and no threat actor campaigns are known. However, the vulnerability's nature (memory corruption in a widely used chipset) makes it attractive for targeted attacks, especially by advanced persistent threats (APTs) focusing on mobile or embedded platforms.

Detection Guidance

Sigma Rule

title: Potential Exploitation of CVE-2026-25291 - Concurrent Memory Page List Corruption
id: 3a4b5c6d-7e8f-9a0b-1c2d-3e4f5a6b7c8d
status: experimental
description: Detects potential attempts to exploit CVE-2026-25291 by monitoring for abnormal memory management operations or crashes related to page list corruption.
author: Threat Intelligence Team
date: 2026-01-01
logsource:
  product: linux
  service: kernel
detection:
  selection:
    EventID: 1  # Process creation, adjust for specific OS
    Image|endswith:
      - '/system/bin/'
      - '/vendor/bin/'
    CommandLine|contains:
      - 'mmap'
      - 'munmap'
      - 'mprotect'
  condition: selection
falsepositives:
  - Legitimate memory management operations
level: medium
tags:
  - attack.t1068
  - cve.2026.25291

YARA Rule

rule CVE_2026_25291_Memory_Corruption
{
    meta:
        description = "Detects potential exploitation of CVE-2026-25291 in Qualcomm Sar1165P firmware"
        author = "Threat Intelligence Team"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-25291"
        severity = "high"
    strings:
        $s1 = "Sar1165P" ascii wide nocase
        $s2 = "shared memory page list" ascii wide nocase
        $s3 = "use-after-free" ascii wide nocase
    condition:
        any of them
}

Suricata IDS Rule

alert ip any any -> any any (msg:"CVE-2026-25291 Qualcomm Sar1165P Memory Corruption Attempt"; content:"Sar1165P"; nocase; sid:1000001; rev:1;)

Elastic Detection

process where process.name in ("system_server", "init") and process.command_line : "*mmap*" and process.command_line : "*munmap*"

Splunk SPL Query

index=main sourcetype=syslog ("Sar1165P" OR "shared memory page list" OR "use-after-free") | stats count by host, process, message

Wazuh OSSEC Rule

<group name="qualcomm,cve-2026-25291,">
  <rule id="100001" level="12">
    <decoded_as>json</decoded_as>
    <field name="message">Sar1165P</field>
    <description>CVE-2026-25291: Qualcomm Sar1165P memory corruption attempt detected</description>
    <mitre>
      <id>T1068</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 2/4 (CLAIMED — single source claims patch, not independently confirmed).

1. Immediate mitigations:

   • Limit local access to affected devices. Ensure that only trusted applications are installed and that user privileges are minimized.
   • Monitor for abnormal system crashes or memory corruption indicators that could signal exploitation attempts.
   • If feasible, disable or restrict access to debugging interfaces and developer options that could aid in triggering the race condition.

2. Patch/upgrade steps:

   • Contact Qualcomm or the device manufacturer for a firmware update that addresses CVE-2026-25291. Since the patch is only claimed via NVD and not independently confirmed, verify the availability and authenticity of any update.
   • Apply the firmware update through official channels only. For enterprise-managed devices, use mobile device management (MDM) or firmware update tools to deploy patches.
   • If no patch is available, consider isolating affected devices from sensitive networks or data until a fix is released.

3. Long-term hardening:

   • Implement secure coding practices for concurrent memory management, including proper synchronization primitives (locks, atomic operations) in firmware development.
   • Conduct regular security audits and fuzz testing on firmware components that handle shared memory.
   • Adopt a defense-in-depth strategy: use memory protection mechanisms such as Address Space Layout Randomization (ASLR), Data Execution Prevention (DEP), and kernel-level sandboxing where supported.
   • Monitor vendor advisories and CVE databases for updates on this vulnerability.

References

1. NVD — CVE-2026-25291: https://nvd.nist.gov/vuln/detail/CVE-2026-25291
2. Qualcomm Security Bulletins: https://www.qualcomm.com/company/product-security/bulletins
3. CWE-416: Use After Free — https://cwe.mitre.org/data/definitions/416.html
4. MITRE ATT&CK T1068: Exploitation for Privilege Escalation — https://attack.mitre.org/techniques/T1068/
5. CISA Known Exploited Vulnerabilities Catalog (not listed as of report date): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

No known threat actor campaigns or exploit-in-the-wild evidence are associated with CVE-2026-25291 at this time.