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PatchSiren cyber security CVE debrief

CVE-2026-78129 strongSwan CVE debrief

A vulnerability in strongSwan versions 4.6.2 through 6.0.7 allows for an infinite loop in PKCS#5 decryption, potentially leading to a denial-of-service (DoS) attack. The CVE record was published on 2026-09-11T02:18:34.207Z and has not been modified since then. The NVD entry is currently Undergoing Analysis. This issue affects strongSwan installations, which defenders should assess for potential exposure and prioritize remediation. The vulnerability is related to PKCS#5 decryption and could lead to DoS attacks if exploited.

Vendor
strongSwan
Product
Unknown
CVSS
MEDIUM 5.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-11
Original CVE updated
2026-09-11
Advisory published
2026-09-11
Advisory updated
2026-09-11

Who should care

Defenders responsible for strongSwan installations should assess potential exposure and prioritize remediation. This includes operators managing affected systems, platform administrators, vulnerability management teams, and security teams that need to verify the vulnerability status of strongSwan installations and plan for potential impacts on VPN or IPsec services.

Why it matters

The vulnerability in strongSwan versions 4.6.2 through 6.0.7 allows for an infinite loop in PKCS#5 decryption, potentially leading to a denial-of-service (DoS) attack. Defenders should prioritize verifying the vulnerability status of strongSwan installations and assessing potential exposure.

  • Potential DoS attacks against strongSwan installations
  • Need to verify vulnerability status of strongSwan installations
  • Potential impact on VPN or IPsec services

Technical summary

The vulnerability in strongSwan versions 4.6.2 through 6.0.7 allows for an infinite loop in PKCS#5 decryption, potentially leading to a denial-of-service (DoS) attack. This technical issue arises from the PKCS#5 decryption process and could impact VPN or IPsec services. Defenders should focus on verifying the vulnerability status of strongSwan installations and assessing potential exposure to prioritize remediation.

Defensive priority

Defenders should prioritize verifying the vulnerability status of strongSwan installations and assessing potential exposure.

Recommended defensive actions

  • Verify the vulnerability status of strongSwan installations
  • Assess potential exposure and prioritize remediation
  • Monitor for potential DoS attacks

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability, with the NVD entry currently listed as Undergoing Analysis. There is no explicit evidence of exploitation or detailed impact, but defenders should verify the vulnerability status of strongSwan installations and assess potential exposure. The lack of detailed information necessitates a cautious approach, focusing on verifying affected scope and vendor guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-78129 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-78129

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-78129 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-78129

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.