CVE-2026-25274

Executive Summary

CVE-2026-25274 is a memory corruption vulnerability (use-after-free, CWE-416) in Qualcomm Aqt1000 firmware that manifests when concurrent DMA buffer allocation and deallocation commands are processed without proper synchronization. The flaw is locally exploitable by an actor already holding high privileges on the device, and successful exploitation yields high impact to confidentiality, integrity, and availability. Qualcomm Aqt1000 targets automotive/embedded platforms, so affected systems are typically in-vehicle or embedded edge devices where firmware patching cycles are long and physical/adjacent access is often assumed rather than prevented.

Technical Analysis

The NVD description states the root cause directly: "Memory Corruption when processing concurrent DMA buffer allocation and deallocation commands without proper synchronization." Three technical facts are derivable from this text alone and are treated as authoritative for this report:

1. Vulnerability class: Memory corruption, mapped by the CNA to CWE-416 (Use After Free). A use-after-free arises when a memory region is released by one execution context (or code path) while another context continues to hold and dereference a pointer to that region. The classic consequence is that the freed object is either re-allocated for a different purpose (type confusion / control-data corruption) or a stale pointer is dereferenced into attacker-influenced content.

2. Triggering mechanism: The corruption is tied to concurrency — specifically, concurrent DMA buffer allocation and deallocation. DMA buffers are regions of memory shared between the host processor and a DMA-capable engine, mapped for direct device access. When allocation and deallocation of these buffers are not serialized (no proper synchronization — e.g., missing or incorrect locking around the buffer lifecycle), two racing operations can interleave such that a deallocation completes before or during an allocation that still references the same buffer slot. The result is a dangling reference within the buffer-management path.

3. Attack surface: DMA buffer management is a privileged surface. The CVSS vector (PR:H) confirms that the attacker must already possess high privileges to reach the vulnerable code path — this is not an unauthenticated or low-privilege bug. The intent is therefore escalation within an already-compromised or highly privileged context, or elevation from a high-privilege firmware context into memory that would otherwise be isolated (e.g., the DMA/secure region).

No function names, call sites, IPC opcodes, or parameter names are disclosed by the NVD description or CNA title. Any assertion of specific identifiers (e.g., named ioctl handlers or HAL routines) would be fabrication and is deliberately omitted. The attack chain in the following section is therefore described at the vulnerability-class level.

Because the target is firmware, the practical exploitation primitive is corruption of the DMA/shared-memory region. Depending on the allocator's layout and the privileges of the racing contexts, an attacker who wins the race may achieve: reallocation of a freed buffer to a sensitive object (leading to control-data corruption), arbitrary write into a buffer whose content is interpreted by a DMA engine, or denial of service via unrecoverable memory-state corruption and subsequent device fault.

Exploitation Scenarios

No public PoC, Nuclei template, or exploit code exists for this CVE. The chain below is inferred strictly from the vulnerability class (CWE-416) and the concurrency/DMA trigger described in the NVD text; specific implementation identifiers are not available and are not invented.

1. Reconnaissance / target identification. The attacker first establishes what firmware and DMA-buffer-management path is reachable from their current privilege level. Given PR:H, the actor is already executing with high privileges on the device (e.g., a firmware component, a privileged process, or physical/adjacent access with debug privileges). Reconnaissance focuses on identifying the interface through which DMA buffer allocation and deallocation commands are issued and confirming that concurrent issuance is possible.

2. Triggering the flaw class. The actor issues concurrent DMA buffer allocation and deallocation commands — deliberately racing the two operations against the same buffer region. Because synchronization around the buffer lifecycle is improper, the deallocation path and the allocation path can interleave, leaving a stale reference: the UAF condition. The race window is the core exploit primitive; the attacker's goal is to widen this window (e.g., by commanding repeated concurrent cycles) until the interleaving is reliably hit.

3. Execution method (vulnerability-class level). Once a freed DMA buffer can be re-referenced, the attacker attempts to reclaim the freed region with controlled content before the stale reference is dereferenced. In firmware/DMA contexts this is typically achieved by steering a subsequent allocation of the same size class into the freed slot. The re-dereference then performs operations on attacker-influenced memory, corrupting control-adjacent data. No public exploit demonstrates this step for CVE-2026-25274.

4. Post-exploitation impact. Per CVSS C:H/I:H/A:H, successful corruption yields high confidentiality, integrity, and availability impact within the affected component's scope. In DMA firmware, this ranges from arbitrary read/write within the shared-memory region to malformed DMA descriptors and device instability/crash. Scope is rated S:U — the corruption impacts the vulnerable firmware component rather than an assumed broader trust boundary in the CVSS model, though in embedded designs a compromised DMA path frequently has downstream effects on the wider system.

Impact Assessment

• Confidentiality (C:H): Corruption of DMA/shared-memory structures can expose data moved through the DMA path.
• Integrity (I:H): Attacker-influenced content can be interpreted as legitimate DMA buffer content or control structures.
• Availability (A:H): Memory-state corruption in firmware frequently produces hard faults, watchdog resets, or unrecoverable device failure.
• Attack Vector (AV:L) / Privileges Required (PR:H): Exploitation is local and requires pre-existing high privileges. This substantially lowers remote exploitability and shrinks the realistic attacker set to those already holding privileged access — but it also means the CVE is an excellent internal escalation primitive rather than a perimeter entry point.
• EPSS 0.00115 (~1.4th percentile): Extremely low predicted exploitation probability. Combined with no PoC, no Nuclei template, and CISA KEV = NO, current exploitation likelihood in the wild is assessed as very low.
• Blast radius: Confined to devices running the affected Qualcomm Aqt1000 firmware. Because firmware updates on embedded/automotive devices are infrequent and often gated by OEM validation cycles, the population of exposed, unpatched units is likely to persist well beyond the disclosure date.

Detection Guidance

Sigma Rule

title: Suspicious Concurrent DMA Buffer Allocation/Deallocation (CVE-2026-25274)
id: 7b1c9e42-2f6d-4c8a-9e10-aa3d5f2b7c01
status: experimental
description: Detects repeated concurrent DMA buffer alloc/free activity consistent with racing the buffer lifecycle for CVE-2026-25274.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-25274
author: Threat Intelligence
date: 2026/02/01
logsource:
  product: linux
  service: kernel
detection:
  selection_dma:
    message|contains:
      - 'dma'
      - 'dma_buf'
      - 'buffer alloc'
      - 'buffer free'
  selection_concurrent:
    message|contains:
      - 'race'
      - 'concurrent'
      - 'use-after-free'
      - 'use after free'
      - 'slab'
  condition: selection_dma and selection_concurrent
falsepositives:
  - Legitimate high-throughput DMA workloads
level: medium

YARA Rule

rule CVE_2026_25274_Aqt1000_DMA_UAF
{
    meta:
        description = "Heuristic detection of Qualcomm Aqt1000 DMA buffer handler with unsynchronized alloc/free paths (CVE-2026-25274)"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-25274"
        author = "Threat Intelligence"
        date = "2026-02-01"
        severity = "medium"

    strings:
        $aqt = "Aqt1000" ascii wide nocase
        $dma_alloc = "dma_alloc" ascii
        $dma_free  = "dma_free" ascii
        $buffer = "buffer" ascii nocase

    condition:
        uint32(0) == 0x464C457F and
        $aqt and
        ($dma_alloc and $dma_free) and
        $buffer
}

Suricata IDS Rule

Network visibility into local DMA firmware races is limited; this rule targets management/telemetry channels that would carry anomalous alloc/free signaling. Where DSCP/direction is not observable on-site, the rule is best deployed on the device's management interface only.

alert udp any any -> any 5353 (msg:"CVE-2026-25274 Qualcomm Aqt1000 DMA alloc/free race activity"; flow:to_server; content:"dma"; nocase; content:"alloc"; nocase; within:64; content:"free"; nocase; within:128; threshold:type both, track by_src, count 20, seconds 5; reference:cve,2026-25274; classtype:attempted-admin; sid:20002601; rev:1;)

Elastic Detection

sequence by host.id with maxspan=2s
  [ process where event.category == "process" and process.name : "*dma*" ]
  [ process where event.action == "end" and process.name : "*dma*" ]

Splunk SPL Query

index=main (source=*firmware* OR source=*kernel* OR source=*aqt1000*)
| search ("dma buffer" OR "dma_alloc" OR "dma_free" OR "buffer allocation")
    (alloc AND free AND (concurrent OR race OR "use-after-free" OR slab OR corruption))
| stats count min(_time) as first_seen max(_time) as last_seen by host, process, message
| where count > 5
| eval first_seen=strftime(first_seen,"%Y-%m-%d %H:%M:%S"), last_seen=strftime(last_seen,"%Y-%m-%d %H:%M:%S")
| table host process count first_seen last_seen message

Wazuh OSSEC Rule

<group name="cve_2026_25274,qualcomm,dma,">
  <rule id="100301" level="8">
    <decoded_as>syslog</decoded_as>
    <match>dma</match>
    <regex>alloc|free|buffer</regex>
    <description>CVE-2026-25274: Suspicious concurrent DMA buffer alloc/free activity (Qualcomm Aqt1000 potential UAF)</description>
  </rule>
  <rule id="100302" level="12">
    <if_sid>100301</if_sid>
    <regex>use-after-free|use after free|slab|corruption|race</regex>
    <description>CVE-2026-25274: DMA buffer concurrency corruption indicators detected (escalate)</description>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source; no vendor fix, no workarounds published).

1. Immediate mitigations

   • Restrict access to any interface capable of issuing DMA buffer allocation/deallocation commands to the minimum set of privileged processes. Because PR:H is required, reducing the number of high-privilege contexts materially shrinks the attack surface.
   • Where the platform permits, serialize or rate-limit concurrent DMA buffer lifecycle operations at the commanding layer rather than relying on firmware-side synchronization.
   • Monitor device health for unexplained resets, watchdog events, or memory faults in DMA/firmware subsystems; these are plausible early indicators of the corruption being triggered.
   • Disable unused DMA-capable peripherals/interfaces to eliminate reachable allocation/free paths.

2. Patch / upgrade steps

   • No vendor patch or fixed version is currently available from any tracked source. Monitor Qualcomm's security bulletin stream and the Aqt1000 product security advisory page for a firmware release addressing CVE-2026-25274.
   • When a fixed firmware image is released, validate the version string contains the CVE fix before rolling out; do not assume a date-later build is patched.
   • Coordinate rollout through the OEM/vehicle integrator, as Aqt1000 firmware is typically distributed via OEM update channels, not directly.

3. Long-term hardening

   • Enforce hardware/kernel-level synchronization primitives (locking or lock-free reference counting) around DMA buffer lifecycle management as a design requirement; treat UAF in DMA paths as a release blocker.
   • Isolate DMA-capable components (IOMMU/SMMU-style memory protection where supported) so that a corrupted buffer cannot be dereferenced into unrelated memory.
   • Audit DMA buffer management code for other unsynchronized alloc/free paths — CWE-416 findings rarely appear alone.
   • Establish firmware SBOM and vulnerability tracking so that Aqt1000 and associated DMA components are continuously matched against new CVEs.
   • Retire or firmly segregate end-of-support embedded firmware from privileged networks where a firmware patch is unlikely to arrive.

References

1. NVD — CVE-2026-25274: https://nvd.nist.gov/vuln/detail/CVE-2026-25274
2. CWE-416 — Use After Free: https://cwe.mitre.org/data/definitions/416.html
3. MITRE ATT&CK T1068 — Exploitation for Privilege Escalation: https://attack.mitre.org/techniques/T1068/
4. CISA Known Exploited Vulnerabilities Catalog (CVE-2026-25274 NOT listed): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
5. Qualcomm Security Bulletins (monitor for Aqt1000 firmware fix): https://www.qualcomm.com/company/product-security/bulletins

No threat actor campaigns, exploit-in-the-wild evidence, or public PoC references were identified for CVE-2026-25274 at the time of writing. EPSS 0.00115 (1.4th percentile) and absence from CISA KEV both indicate negligible observed exploitation activity.