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CVE Record

CVE-2026-3497: Vulnerability in the OpenSSH GSSAPI delta included in various Linux distributions.

Vulnerability in the OpenSSH GSSAPI delta included in various Linux distributions. This vulnerability affects the GSSAPI patches added by various Linux distributions and does not affect the OpenSSH upstream project itself. The usage of sshpkt_disconnect() on an error, which does not terminate the process, allows an attacker to send an unexpected GSSAPI message type during the GSSAPI key exchange to the server, which will call the underlying function and continue the execution of the program without setting the related connection variables. As the variables are not initialized to NULL the code later accesses those uninitialized variables, accessing random memory, which could lead to undefined behavior. The recommended workaround is to use ssh_packet_disconnect() instead, which does terminate the process. The impact of the vulnerability depends heavily on the compiler flag hardening configuration.

HighCVSS 8.2Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This is a high-severity flaw in some Linux distribution patches to OpenSSH, not in upstream OpenSSH itself. A remote unauthenticated attacker can trigger faulty GSSAPI key-exchange handling that may destabilize sshd. The main business concern is SSH service availability, with limited confidentiality impact reported.

Executive priority

Treat as urgent for internet-exposed SSH servers on affected Linux distributions, especially production access gateways. Prioritize patching over emergency shutdown unless vendor guidance or local exposure analysis indicates a higher operational risk.

Technical view

During GSSAPI key exchange, an unexpected message can reach sshpkt_disconnect(), which does not terminate execution. Connection variables remain uninitialized and may later be dereferenced, causing undefined behavior. CVSS 3.1 is 8.2: network, low complexity, no privileges, no user interaction, confidentiality low, availability high.

Likely exposure

Exposure is most likely on Linux systems running distribution-patched OpenSSH packages that include the GSSAPI delta. The bundle names Ubuntu openssh versions and includes Debian and Red Hat advisories, but does not provide complete affected-version detail for every distribution.

Exploitation context

The bundle does not show CISA KEV listing or cited evidence of active exploitation. The flaw is remotely reachable before authentication when the affected GSSAPI key-exchange path is present, but practical impact depends heavily on compiler hardening configuration.

Researcher notes

Do not generalize this to all OpenSSH. The vulnerable code is described as a distribution GSSAPI delta. The source bundle names the bug class as uninitialized pointer/read behavior, with availability impact dominant and exploitability shaped by compiler hardening.

Mitigation direction

  • Apply vendor OpenSSH security updates for affected Linux distributions.
  • Check Ubuntu openssh versions against the Ubuntu CVE advisory.
  • Review Debian LTS and Red Hat errata for applicable fixed packages.
  • If patching is delayed, follow vendor-specific mitigation guidance.
  • Confirm any source-level workaround with the vendor before relying on it.

Validation and detection

  • Inventory systems running distribution-provided OpenSSH server packages.
  • Identify whether installed packages match affected vendor versions or errata.
  • Verify upstream-only OpenSSH builds separately; upstream is stated unaffected.
  • Check whether GSSAPI key exchange is present in the deployed build.
  • After updates, confirm package versions match vendor fixed releases.
Prepared
Confidence
medium
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-824: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cwe · low confidence lookup

CWE-908: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2026-3497 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.2 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
4ADP providers
37Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.2CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H3.94.2redhat-SADP
2.7CVSS 4.0LowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N——canonical

Vulnerability scoring details

Base CVSS 4.0 score

2.7Low
CVSS 4.0 vector shape for CVE-2026-3497Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container
redhat-SADPopenssh: OpenSSH GSSAPI: Information disclosure or denial of service due to uninitialized variables
other:Red Hat severity ratingcvssV3_1
  • 2026-03-12T19:01:37.007Z: Reported to Red Hat.
  • 2026-03-12T18:27:44.917Z: Made public.
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Ubuntuopensshopenssh, 1:10.0p1-5ubuntu5, 1:9.6p1-3ubuntu13, 1:8.9p1-3unaffected
Weakness

CWE details

CWE-824CWE-908

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-824 · source CWE mapping

Access of Uninitialized Pointer

Access of Uninitialized Pointer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-908 · source CWE mapping

Use of Uninitialized Resource

Use of Uninitialized Resource represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs