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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

A flaw in distribution-added OpenSSH GSSAPI code can let an unauthenticated remote attacker crash an affected SSH server and potentially expose limited memory. Upstream OpenSSH is not affected. Actual impact varies with compiler hardening, so organizations must assess distribution packages rather than relying only on the upstream OpenSSH version.

Executive priority

Treat this as a high-priority patching issue for exposed Linux SSH servers, especially where GSSAPI is available. It is not evidence of an upstream OpenSSH-wide emergency or confirmed active exploitation. Request rapid inventory and vendor-update deployment, with operational monitoring until coverage is verified.

Technical view

During GSSAPI key exchange, an unexpected message invokes sshpkt_disconnect(), which does not terminate processing. Execution continues without initializing connection variables, leading to access of indeterminate memory and undefined behavior. The CVSS 3.1 score is 8.2, reflecting network access, low complexity, no privileges or interaction, limited confidentiality impact, and high availability impact.

Likely exposure

Exposure is concentrated in Linux distributions carrying the affected GSSAPI patch, including identified Ubuntu OpenSSH package versions and products covered by Debian and Red Hat advisories. Internet-reachable SSH services using the affected package and GSSAPI path deserve priority. Upstream-only OpenSSH builds are outside the described scope.

Exploitation context

The vulnerable path is reachable remotely before authentication during GSSAPI key exchange. The supplied record is not in KEV and provides no evidence of active exploitation. Undefined behavior may cause denial of service or limited memory disclosure; practical results depend heavily on build-time compiler hardening.

Researcher notes

Assessment should distinguish downstream GSSAPI deltas from upstream OpenSSH. Review the unexpected-message error path, variable initialization, process termination semantics, and compiler hardening. The supplied evidence supports undefined memory access, availability loss, and limited confidentiality impact, but does not establish reliable code execution or exploitation in the wild.

Mitigation direction

  • Apply the applicable Linux distributor's security update or erratum after normal compatibility testing.
  • Prioritize affected SSH servers that are internet-reachable or permit GSSAPI authentication.
  • Downstream maintainers should replace sshpkt_disconnect() with the terminating ssh_packet_disconnect(), following vendor guidance.
  • Consult the exact distributor advisory when no confirmed fixed package is available.

Validation and detection

  • Inventory OpenSSH packages by distribution, release, architecture, and installed package version.
  • Compare installed packages with Ubuntu, Debian, or Red Hat advisory status and fixed builds.
  • Identify whether GSSAPI authentication is enabled and reachable on each affected SSH service.
  • After updating, confirm package provenance, restart requirements, and successful SSH authentication.
  • Monitor SSH service crashes and abnormal GSSAPI negotiation failures while remediation proceeds.
Prepared
Confidence
high
Sources
8

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