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01 Record

CVE-2026-47778

Envoy: Embedded NUL in TLS DNS SAN Truncation in the Default TLS Certificate Validator. (Auth Bypass)

MediumPUBLISHEDCNA: GitHub_M
CNA base score4.4 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N

02 Description

Envoy: Embedded NUL in TLS DNS SAN Truncation in the Default TLS Certificate Validator. (Auth Bypass)

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.21% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 11.4% of scored records. A rank, not a probability.
NVD base score
4.4 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N
NVD analysis status
Analyzed. NVD last modified this record on 2026-10-25.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-06-26 17:27Z4 MO AGO
Last updated
2026-06-27 02:53Z4 MO AGO
Reserved
2026-05-19
Assigning CNA
GitHub_M
Record state
PUBLISHED
Severity
Medium (CVSS 4.4)
CNA CVSS vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N
Weaknesses
  • CWE-158Improper Neutralization of Null Byte or NUL CharacterVariant
  • CWE-170Improper Null TerminationBase
Data version
5.2
Document digest
b66c69f140852b818292a3a6e7ba14377e3d2478288c625013bba33262f909a2

05 Affected products

VendorProductVersionsPlatforms
envoyproxyenvoy>= 1.38.0, < 1.38.1, >= 1.37.0, < 1.37.3, >= 1.36.0, < 1.36.7, < 1.35.11—

06 References