Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated remote party crash the strongSwan charon IKE daemon during IKEv2 authentication. For organizations using strongSwan for VPN or IPsec access, the business impact is service outage, not documented data theft or takeover in the supplied sources.
Executive priority
Prioritize patching exposed VPN gateways because a remote unauthenticated outage against remote-access infrastructure can disrupt operations. This is high urgency for availability, but the supplied evidence does not show confidentiality impact or confirmed active exploitation.
Technical view
strongSwan 4.5.0 before 6.0.5 has an integer underflow in EAP-TTLS AVP length handling. Invalid AVP length fields can lead to excessive allocation or NULL pointer dereference, causing denial of service in charon. The supplied CVSS v4 score is 8.7 with high availability impact.
Likely exposure
Internet-facing or partner-facing strongSwan IKEv2 deployments are most relevant, especially where EAP-TTLS authentication is enabled. Deployments not using EAP-TTLS, not exposing IKEv2, or already on fixed vendor packages are less likely exposed.
Exploitation context
The bundle cites exploit-tagged public references, but KEV is false and the provided sources do not establish active exploitation in the wild. Treat the issue as remotely reachable and easy to trigger where the vulnerable authentication path is exposed.
Researcher notes
Focus validation on EAP-TTLS AVP parsing reachability in charon, version provenance, and vendor backport status. Avoid assuming all strongSwan deployments are exploitable; exposure depends on IKEv2 accessibility and EAP-TTLS configuration.
Mitigation direction
- Upgrade strongSwan to 6.0.5 or a vendor package containing the fix.
- Apply relevant distribution security updates, including Debian LTS guidance where applicable.
- Review whether EAP-TTLS is required on exposed IKEv2 services.
- Restrict IKEv2 exposure to trusted networks where operationally feasible.
- Monitor charon crashes and authentication failure spikes until patched.
Validation and detection
- Inventory strongSwan versions across VPN and IPsec gateways.
- Confirm whether each deployment exposes IKEv2 to untrusted networks.
- Check configuration for EAP-TTLS authentication use.
- Verify installed packages include the 6.0.5 fix or vendor backport.
- Review logs for recent charon crashes during authentication attempts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-191: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-476: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-25075 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6VulnCheckVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://www.strongswan.org/blog/2026/03/23/strongswan-vulnerability-(cve-2026-25075).htmlCVE reference, VulnCheck · vendor-advisory, exploit
- https://www.strongswan.org/blog/2026/03/23/strongswan-6.0.5-released.htmlCVE reference, VulnCheck · release-notes
- https://y637f9qq2x.com/posts/cve-2026-25075/CVE reference, VulnCheck · technical-description, exploit
- https://www.vulncheck.com/advisories/strongswan-eap-ttls-avp-parsing-integer-underflowCVE reference, VulnCheck · third-party-advisory
- https://lists.debian.org/debian-lts-announce/2026/03/msg00016.htmlCVE reference, CVE
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Integer Underflow (Wrap or Wraparound)
Integer Underflow (Wrap or Wraparound) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.