CVE-2026-21371 — Buffer Over-read in WinBlast Driver
Memory Corruption when retrieving output buffer with insufficient size validation.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.1% (30-day exploitation probability)+0
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Qualcomm Aqt1000 Firmware, Qualcomm Cologne Firmware, Qualcomm Fastconnect 6200 Firmware…).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Qualcomm | Aqt1000 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Cologne Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Fastconnect 6200 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Fastconnect 6700 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Fastconnect 6800 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Fastconnect 6900 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Fastconnect 7800 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Qca0000 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Qca6391 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Qca6420 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Qca6430 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Qcm5430 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Qcm6490 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Sc8380xp Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Sm6250 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon |
version AQT1000version Cologneversion FastConnect 6200version FastConnect 6700version FastConnect 6800version FastConnect 6900version FastConnect 7800version QCA0000 and 44 moreversion QCA6391version QCA6420version QCA6430version QCM5430version QCM6490version Qualcomm Video Collaboration VC3 Platformversion SC8380XPversion SM6250version Snapdragon 460 Mobile Platformversion Snapdragon 662 Mobile Platformversion Snapdragon 7c Compute Platformversion Snapdragon 7c Gen 2 Compute Platform "Rennell Pro"version Snapdragon 7c+ Gen 3 Computeversion Snapdragon 8c Compute Platform "Poipu Lite"version Snapdragon 8c Compute Platform (SC8180XP-AD) "Poipu Lite"version Snapdragon 8cx Compute Platformversion Snapdragon 8cx Compute Platform "Poipu Pro"version Snapdragon 8cx Gen 2 5G Compute Platformversion Snapdragon 8cx Gen 2 5G Compute Platform "Poipu Pro"version Snapdragon 8cx Gen 3 Compute Platformversion WCD9340version WCD9341version WCD9370version WCD9375version WCD9378Cversion WCD9380version WCD9385version WCN3950version WCN3988version WSA8810version WSA8815version WSA8830version WSA8835version WSA8840version WSA8845version WSA8845Hversion X2000077version X2000086version X2000090version X2000092version X2000094version XG101002version XG101032version XG101039 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Qualcomm | Snapdragon 460 Mobile Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 662 Mobile Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 7c Compute Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 7c Gen 2 Compute Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 7c+ Gen 3 Compute Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 8c Compute Platform (sc8180xp-ad) Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 8c Compute Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 8cx Compute Platform "poipu Pro" Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 8cx Compute Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 8cx Gen 2 5g Compute Platform "poipu Pro" Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 8cx Gen 2 5g Compute Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Snapdragon 8cx Gen 3 Compute Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Video Collaboration Vc3 Platform Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcd9340 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcd9341 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcd9370 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcd9375 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcd9378c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcd9380 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcd9385 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcn3950 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wcn3988 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wsa8810 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wsa8815 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wsa8830 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wsa8835 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wsa8840 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wsa8845 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Wsa8845h Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | X2000077 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | X2000086 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | X2000090 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | X2000092 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | X2000094 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Xg101002 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Xg101032 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Qualcomm | Xg101039 Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | product-security@qualcomm.com via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | qualcomm via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: product-security@qualcomm.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.10%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · qualcomm, inc./snapdragon
- SSVC assessment updated
- Record published
- CVSS changed · 7.8
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-57559 Use After Free in DSP_Services 9d
- High CVE-2026-57554 Use After Free in DSP Service 9d
- High CVE-2026-57555 Use After Free in DSP Service 9d
- High CVE-2026-57545 Untrusted Pointer Dereference in Graphics 9d
- High CVE-2026-57537 Use After Free in DSP Service 9d
- High CVE-2026-25302 Improper Verification of Cryptographic Signature in Boot 9d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-21371 is "Buffer Over-read in WinBlast Driver", rated High. It affects Aqt1000 Firmware (Qualcomm); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.10% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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