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CVE Record

CVE-2026-6245: Sssd: out-of-bounds read in the sssd

A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A local, low-privileged user may be able to crash SSSD by submitting a crafted passkey authentication request. This can interrupt authentication services on affected Red Hat systems. The supplied assessment rates the issue CVSS 5.5, with availability impact but no identified confidentiality or integrity impact.

Executive priority

Treat as a moderate availability risk. Prioritize authentication-critical hosts and passkey-enabled environments, but the supplied evidence does not justify emergency, enterprise-wide action. Obtain exact affected-version and remediation details from Red Hat before scheduling deployment.

Technical view

SSSD's PAM passkey responder treats raw pipe data as a NUL-terminated C string without ensuring termination. Subsequent string processing can read beyond the buffer and crash the PAM responder. The issue is classified as CWE-805 and requires local access with low privileges; user interaction is not required.

Likely exposure

Potential exposure includes systems using the listed SSSD packages across RHEL 6–10 and listed RHEL CoreOS packages in OpenShift 4. Exact vulnerable package versions are absent from the supplied sources, so installation alone cannot confirm vulnerability. Passkey authentication use may affect practical reachability.

Exploitation context

The described scenario is local denial of service through a crafted passkey authentication request. The bundle reports no CISA KEV listing and provides no evidence of active exploitation, public exploitation, remote reachability, data theft, privilege escalation, or code execution.

Researcher notes

CVSS 3.1 is 5.5: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. The vulnerable function is pam_passkey_child_read_data(). Evidence supports an unterminated-buffer out-of-bounds read and crash outcome. Exact affected versions, fixed versions, reproducer details, and exploit prevalence are not supplied.

Mitigation direction

  • Check Red Hat's CVE advisory and Bugzilla entry for current package-specific remediation guidance.
  • Inventory SSSD packages on RHEL 6–10 and relevant RHEL CoreOS nodes in OpenShift 4.
  • Prioritize systems using SSSD passkey authentication or where authentication availability is operationally critical.
  • Apply vendor-provided updates when identified, following normal testing and deployment controls.

Validation and detection

  • Record installed SSSD or RHEL CoreOS package versions on potentially affected systems.
  • Compare installed packages with Red Hat's current advisory status and package-specific guidance.
  • Determine whether SSSD PAM passkey authentication is configured and reachable by local low-privileged users.
  • Review SSSD and authentication-service logs for unexplained PAM responder crashes or service interruptions.
Prepared
Confidence
medium
Sources
4

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-805: 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.

Open ATT&CK lookup
description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-6245 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
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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.

1CVSS vectors
5Timeline events
1ADP providers
3Source links

SSVC decision data

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

CVSS vector scores

1 official score

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
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6redhat

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2026-6245Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
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. Source timelineredhat

    Reported to Red Hat.

  3. Source timelineredhat

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

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

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Red HatRed Hat Enterprise Linux 10sssdaffected
Red HatRed Hat Enterprise Linux 6sssdaffected
Red HatRed Hat Enterprise Linux 7sssdaffected
Red HatRed Hat Enterprise Linux 8sssdaffected
Red HatRed Hat Enterprise Linux 9sssdaffected
Red HatRed Hat OpenShift Container Platform 4openshift/ose-rhel-coreos-8affected
Red HatRed Hat OpenShift Container Platform 4openshift/ose-rhel-coreos-9affected
Weakness

CWE details

CWE-805

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

CWE-805 · source CWE mapping

Buffer Access with Incorrect Length Value

Buffer Access with Incorrect Length Value represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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