CVE-2026-13465 — EL3 Stack Buffer Overflow in FCS HKDF Request
Stack-based buffer overflow vulnerability in Altera Trusted Firmware on HPS allows Exploitation of Improperly Configured or Implemented Memory Protections. This issue affects Trusted Firmware: through socfpga_v2.14.0.
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 (Altera Trusted Firmware).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Altera | Trusted Firmware | ≤ socfpga_v2.14.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
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 |
|---|---|---|---|---|---|
| 8.3 | CVSS 4.0 | High | — | — | 04c0172e-9735-4a9d-a92a-fe01fa863447 via NIST National Vulnerability Database |
| 8.3 | CVSS 4.0 | High | — | — | Altera via CVE Program (cve.org) e CISA ADP |
| 8.1 | CVSS 3.1 | High | 1.5 | 6.0 | 04c0172e-9735-4a9d-a92a-fe01fa863447 via NIST National Vulnerability Database |
| 8.1 | CVSS 3.1 | High | — | — | Altera via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:L/I:H/A:H (score shown at the top: 04c0172e-9735-4a9d-a92a-fe01fa863447) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
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.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · altera/trusted firmware
- SSVC assessment updated
- Record published
- CVSS changed · 8.1
- Source status changed · → Awaiting Analysis
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-58007 Unchecked SDM mailbox response address enables EL3 secure-memory corruption 22d
- High CVE-2026-58008 Unchecked HKDF key-size input in EL3 causes a stack buffer overflow 22d
- High CVE-2026-58004 Crafted oversized firmware image causes EL3 stack overflow during VAB authentication on Trusted Firmware. 22d
- High CVE-2026-58005 Unvalidated SiP v2 mailbox pointers allow non-secure EL1 access to arbitrary physical addresses through EL3. 22d
- High CVE-2026-58006 Altera SoCFPGA BL31 Mailbox Output Pointer Validation Enables EL3 Secure-Memory Corruption 22d
- High CVE-2026-13466 Unit Confusion in VAB Authentication 22d
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-2026-13465 is "EL3 Stack Buffer Overflow in FCS HKDF Request", rated High. It affects Trusted Firmware (Altera); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 0.11% 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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