CVE-2026-39830 (GCVE-0-2026-39830)

Vulnerability from cvelistv5 – Published: 2026-05-22 02:31 – Updated: 2026-05-22 18:54
VLAI
Title
Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh
Summary
A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.
Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CWE
Assigner
Go
References
Impacted products
Vendor Product Version
golang.org/x/crypto golang.org/x/crypto/ssh Affected: 0 , < 0.52.0 (semver)
Create a notification for this product.
Credits
NCC Group Cryptography Services, sponsored by Teleport
Show details on NVD website
To clipboard 

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              "confidentialityImpact": "HIGH",
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              "name": "tcpListener.Close"
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          "url": "https://go.dev/cl/781640"
        },
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          "url": "https://go.dev/cl/781664"
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        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5017"
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      "title": "Invoking  client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh"
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.