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PatchSiren cyber security CVE debrief

CVE-2026-55967 wolfSSL CVE debrief

The CVE-2026-55967 vulnerability involves AES-GCM encryption/decryption with extremely large cumulative single message sizes (>64 GiB) not being properly rejected by the streaming APIs, allowing counter wrap, keystream reuse, and consequent plaintext recovery. This issue affects systems using WolfSSL for AES-GCM encryption/decryption with large message sizes. Defenders and security teams should assess exposure and prioritize mitigation. The vulnerability has a CVSS score of 2 and a severity of LOW. The CVE record was published on 2026-06-25T18:16:41.330Z and has not been modified since then.

Vendor
wolfSSL
Product
Unknown
CVSS
LOW 2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-25
Original CVE updated
2026-10-24
Advisory published
2026-06-25
Advisory updated
2026-10-24

Who should care

Defenders and security teams using WolfSSL for AES-GCM encryption/decryption with large message sizes should assess exposure and prioritize mitigation.

Why it matters

Defenders should care about CVE-2026-55967 because it involves a vulnerability in AES-GCM encryption/decryption with large cumulative single message sizes, potentially leading to counter wrap, keystream reuse, and plaintext recovery. Security teams using WolfSSL should assess exposure and prioritize mitigation.

  • Potential for counter wrap and keystream reuse in AES-GCM encryption/decryption
  • Consequent plaintext recovery in systems using large message sizes
  • Need for verification and mitigation in systems using WolfSSL

Technical summary

The CVE-2026-55967 vulnerability involves AES-GCM encryption/decryption with extremely large cumulative single message sizes (>64 GiB) not being properly rejected by the streaming APIs, allowing counter wrap, keystream reuse, and consequent plaintext recovery.

Defensive priority

Defenders should prioritize verifying and mitigating the impact of this vulnerability on systems using large message sizes with AES-GCM encryption.

Recommended defensive actions

  • Verify and update WolfSSL to version 5.9.2 or later
  • Implement proper rejection of large cumulative single message sizes in AES-GCM encryption/decryption
  • Monitor and assess exposure in systems using large message sizes with AES-GCM encryption

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but evidence is limited regarding specific exploitation or impact. The vulnerability was disclosed by WolfSSL, and defenders should verify and mitigate the impact on systems using large message sizes with AES-GCM encryption. The official CVE Program record and NVD detail page provide source-provided CVE metadata and vulnerability assessment. However, further verification is needed to assess exposure and prioritize mitig

Sources and references

Verified primary and authoritative sources

  • CVE-2026-55967 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-55967

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

  • CVE-2026-55967 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-55967

    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.