CVE-2026-78426 go CVE debrief

Who should care

Defenders responsible for configuring and maintaining NeuVector JWT verifier should assess exposure and prioritize verification and potential updates to prevent continued use of non-expired tokens with equivalent spelling of the RSA signature field. They should also verify NeuVector JWT verifier configurations and update to patched versions if available.

Why it matters

Defenders should prioritize verifying NeuVector JWT verifier configurations and updating to patched versions if available due to potential continued use of non-expired tokens.

• Potential continued use of non-expired tokens with equivalent spelling of the RSA signature field
• Verification of NeuVector JWT verifier configurations is required
• Updating to patched versions may be necessary

Technical summary

The NeuVector JWT verifier accepts noncanonical Base64URL encodings of the same RSA signature field, allowing an attacker to continue using a valid JWT that has not expired. This vulnerability affects defenders responsible for configuring and maintaining NeuVector JWT verifier. They should assess exposure and prioritize verification and potential updates to prevent continued use of non-expired tokens with equivalent spelling of the RSA signature field. The vulnerability has a CVSS score of 3.7 and a CVSS severity of LOW.

Defensive priority

Defenders should prioritize verifying NeuVector JWT verifier configurations and updating to patched versions if available.

Recommended defensive actions

• Verify NeuVector JWT verifier configurations
• Update to patched versions if available
• Monitor for non-expired tokens with equivalent spelling of the RSA signature field
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further verification is required to determine the affected versions and potential impact. The vulnerability allows an attacker to continue using a valid JWT that has not expired due to noncanonical Base64URL encodings of the same RSA signature field. Defenders should verify NeuVector JWT verifier configurations and update to patched versions if available.

Sources and 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.