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CVE Record

CVE-2026-0719: Libsoup: signed to unsigned conversion error leading to stack-based buffer overflow in libsoup ntlm authentication

A flaw was identified in the NTLM authentication handling of the libsoup HTTP library, used by GNOME and other applications for network communication. When processing extremely long passwords, an internal size calculation can overflow due to improper use of signed integers. This results in incorrect memory allocation on the stack, followed by unsafe memory copying. As a result, applications using libsoup may crash unexpectedly, creating a denial-of-service risk.

HighCVSS 8.6Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-0719 is a flaw in libsoup's NTLM authentication handling. A specially long password can trigger bad memory sizing and a stack buffer overflow, likely crashing affected applications. The main business risk is service disruption in Red Hat environments using affected libsoup, libsoup3, or spice-client-win packages.

Executive priority

Treat as a high-priority Linux platform patching issue, especially where NTLM-enabled network applications support business operations. The known evidence points mainly to outage risk, so prioritize availability-critical services before broad desktop or low-impact systems.

Technical view

The flaw is a signed-to-unsigned conversion issue during NTLM password processing in libsoup. An integer overflow can cause undersized stack allocation followed by unsafe copy, mapped to CWE-121. Red Hat rates it high with CVSS 8.6: network reachable, low complexity, no privileges, no user interaction, high availability impact.

Likely exposure

Exposure is most likely on listed Red Hat Enterprise Linux 7 ELS, 8, 8.x extended support streams, and 10 systems with affected libsoup, libsoup3, or spice-client-win packages. Applications must use libsoup's NTLM authentication path to reach the vulnerable behavior.

Exploitation context

The bundle does not show CISA KEV listing or any cited active exploitation. The described trigger is remote and unauthenticated in CVSS terms, but the provided evidence supports crash-oriented denial of service, not confirmed weaponized exploitation or reliable code execution.

Researcher notes

The source bundle identifies the vulnerable area and memory-safety class but does not include patch diffs, proof-of-concept details, or exploit telemetry. Validate exposure by package stream and NTLM usage, and avoid extrapolating beyond Red Hat's affected package list.

Mitigation direction

  • Review Red Hat advisories for affected products and apply vendor-provided package updates.
  • Prioritize systems where libsoup-using applications perform NTLM authentication over networks.
  • Check Red Hat CVE guidance before assuming any workaround or compensating control.
  • Reduce reliance on NTLM paths where operationally feasible until updated.

Validation and detection

  • Inventory RHEL systems for libsoup, libsoup3, and spice-client-win package versions.
  • Map installed packages to the affected Red Hat product streams in the CVE record.
  • Identify applications using libsoup with NTLM authentication enabled or reachable.
  • Confirm remediation against the relevant Red Hat RHSA advisory for each stream.
  • Monitor affected applications for crash patterns until patches are deployed.
Prepared
Confidence
high
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-121: 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
cve · low confidence lookup

CVE-2026-0719 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
8.6 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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
7Timeline events
2ADP providers
24Source links

SSVC decision data

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

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
8.6CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H3.94.7redhat
8.6CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H3.94.7redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

8.6High
CVSS 3.1 vector shape for CVE-2026-0719Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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. ADP timelineredhat-SADP

    Made public.

  2. Source timelineredhat

    Made public.

  3. ADP timelineredhat-SADP

    Reported to Red Hat.

  4. Source timelineredhat

    Reported to Red Hat.

  5. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  6. CVE publishedCVE Program

    The CVE record was published.

  7. CVE updatedCVE Program

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

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPlibsoup: Signed to Unsigned Conversion Error Leading to Stack-Based Buffer Overflow in libsoup NTLM Authentication
other:Red Hat severity ratingcvssV3_1
  • 2026-01-08T12:09:43.352Z: Reported to Red Hat.
  • 2026-01-08T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Red HatRed Hat Enterprise Linux 10libsoup3, 0:3.6.5-3.el10_1.9affected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Supportlibsoup3, 0:3.6.5-3.el10_0.14affected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Supportlibsoup, 0:2.62.2-11.el7_9affected
Red HatRed Hat Enterprise Linux 8spice-client-win, 0:8.10-7affected
Red HatRed Hat Enterprise Linux 8libsoup, 0:2.62.3-13.el8_10affected
Red HatRed Hat Enterprise Linux 8libsoup, 0:2.62.3-13.el8_10affected
Red HatRed Hat Enterprise Linux 8.2 Advanced Update Supportlibsoup, 0:2.62.3-1.el8_2.8affected
Red HatRed Hat Enterprise Linux 8.2 Advanced Update Supportspice-client-win, 0:8.10-7.el8_2.1affected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supportlibsoup, 0:2.62.3-2.el8_4.8affected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supportspice-client-win, 0:8.10-7.el8_4.1affected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-Onlibsoup, 0:2.62.3-2.el8_4.8affected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-Onspice-client-win, 0:8.10-7.el8_4.1affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supportlibsoup, 0:2.62.3-2.el8_6.8affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supportspice-client-win, 0:8.10-7.el8_6.1affected
Red HatRed Hat Enterprise Linux 8.6 Telecommunications Update Servicelibsoup, 0:2.62.3-2.el8_6.8affected
Red HatRed Hat Enterprise Linux 8.6 Telecommunications Update Servicespice-client-win, 0:8.10-7.el8_6.1affected
Red HatRed Hat Enterprise Linux 8.6 Update Services for SAP Solutionslibsoup, 0:2.62.3-2.el8_6.8affected
Red HatRed Hat Enterprise Linux 8.6 Update Services for SAP Solutionsspice-client-win, 0:8.10-7.el8_6.1affected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Servicelibsoup, 0:2.62.3-3.el8_8.8affected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Servicespice-client-win, 0:8.10-7.el8_8.1affected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutionslibsoup, 0:2.62.3-3.el8_8.8affected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutionsspice-client-win, 0:8.10-7.el8_8.1affected
Red HatRed Hat Enterprise Linux 9libsoup, 0:2.72.0-12.el9_7.5affected
Red HatRed Hat Enterprise Linux 9.0 Update Services for SAP Solutionslibsoup, 0:2.72.0-8.el9_0.9affected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutionslibsoup, 0:2.72.0-8.el9_2.10affected
Red HatRed Hat Enterprise Linux 9.4 Extended Update Supportlibsoup, 0:2.72.0-8.el9_4.9affected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Supportlibsoup, 0:2.72.0-10.el9_6.6affected
Red HatRed Hat OpenShift Dev Spaces (RHOSDS) 3.26devspaces/openvsx-rhel9, sha256:619c10386e0224e5228876a434c5b8d78d251bc383e2a9491503d6ceddd33c96affected
Red HatRed Hat OpenShift Dev Spaces (RHOSDS) 3.26devspaces/pluginregistry-rhel9, sha256:48d31aa446fe1033ad770ed74442053bcee5102035a9c618fb81cde1743a9692affected
Red HatRed Hat OpenShift Dev Spaces (RHOSDS) 3.26devspaces/udi-rhel9, sha256:bb9f0ee4fa785a4c3d4a3f6f5e177f4a41350ccef40bc53bfeedee2d52061472affected
Weakness

CWE details

CWE-121

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

CWE-121 · source CWE mapping

Stack-based Buffer Overflow

Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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