CVE-2025-13751 — Allocation of Resources Without Limits or Throttling in Openvpn
Interactive service agent in OpenVPN version 2.5.0 through 2.6.16 and 2.7_alpha1 through 2.7_rc2 on Windows allows a local authenticated user to connect to the service and trigger an error causing a local denial of service.
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 0.2% (30-day exploitation probability)+1
- Technical severity (medium)+3
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 (OpenVPN Openvpn).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| OpenVPN | Openvpn |
≥ 2.5.0 and < 2.6.17version 2.7-alpha1version 2.7-alpha2version 2.7-alpha3version 2.7-beta1version 2.7-beta2version 2.7-beta3version 2.7-rc1 and 1 moreversion 2.7-rc2 |
Vulnerable | NIST National Vulnerability Database |
| OpenVPN | Openvpn | ≥ 2.5.0 and ≤ 2.6.16≥ 2.7_alpha1 and ≤ 2.7_rc2 | 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 |
|---|---|---|---|---|---|
| 1.3 | CVSS 4.0 | Low | — | — | security@openvpn.net via NIST National Vulnerability Database |
| 1.3 | CVSS 4.0 | Low | — | — | OpenVPN via CVE Program (cve.org) e CISA ADP |
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-770 · Allocation of Resources Without Limits or Throttling
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.17%
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.
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · openvpn/openvpn
- SSVC assessment updated
- Record published
- CVSS changed · 5.5
- Source status changed · → Analyzed
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-84471 The fix for CVE-2026-12996 was incomplete. A use-after-free in OpenVPN 2.6.0 through 2.6.22 and 2... 2d
- High CVE-2026-88964 An integer underflow in OpenVPN version 2.7_alpha3 through 2.7.7 on Windows and Android allows... 2d
- High CVE-2026-84790 OpenVPN 2.7_alpha1 through 2.7.7 allows remote authenticated users to impersonate others via a... 2d
- High CVE-2026-84732 Integer Overflow or Wraparound in Openvpn Sep 7, 2026
- Low CVE-2026-81738 Stack-based Buffer Overflow in Openvpn Sep 7, 2026
- Medium CVE-2026-81830 The Windows interactive service in OpenVPN 2.4.0 through 2.6.22 allows local… Sep 7, 2026
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-2025-13751 is "Allocation of Resources Without Limits or Throttling in Openvpn", rated Medium. It affects Openvpn (OpenVPN); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.17% 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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