Vulnerability-Lookup

GHSA-4243-HP56-4M7F

Vulnerability from github – Published: 2026-06-24 06:31 – Updated: 2026-06-24 06:31

Details

An out-of-bounds heap read and integer underflow in the TCP urgent data handling (sosendoob) in freedesktop.org libslirp version before v4.9.2 on hypervisor host environments (e.g., QEMU) allows a privileged guest VM attacker (root or CAP_NET_RAW) to leak gigabytes of sensitive host-process heap memory via sending crafted TCP segments with manipulated URG flags and urgent pointers (ti_urp).

Severity

6.5 (Medium)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-9539"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-24T05:17:31Z",
    "severity": "MODERATE"
  },
  "details": "An out-of-bounds heap read and integer underflow in the TCP urgent data handling (sosendoob) in freedesktop.org libslirp version before v4.9.2 on hypervisor host environments (e.g., QEMU) allows a privileged guest VM attacker (root or CAP_NET_RAW) to leak gigabytes of sensitive host-process heap memory via sending crafted TCP segments with manipulated URG flags and urgent pointers (ti_urp).",
  "id": "GHSA-4243-hp56-4m7f",
  "modified": "2026-06-24T06:31:46Z",
  "published": "2026-06-24T06:31:46Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9539"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.freedesktop.org/slirp/libslirp/-/commit/927bca7344e31fd58e2f7afaca784aad4400eb84"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.freedesktop.org/slirp/libslirp/-/releases/v4.9.2"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.freedesktop.org/slirp/libslirp/-/work_items/93"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-9539 (GCVE-0-2026-9539)

Vulnerability from cvelistv5 – Published: 2026-06-24 04:37 – Updated: 2026-06-24 12:39

Title

libslirp TCP URG OOB Read Information Leak

Summary

Severity

6.5 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-125 - Out-of-bounds read

Assigner

STAR_Labs

References

3 references

URL	Tags
https://gitlab.freedesktop.org/slirp/libslirp/-/w…	issue-tracking
https://gitlab.freedesktop.org/slirp/libslirp/-/c…	patch
https://gitlab.freedesktop.org/slirp/libslirp/-/r…	release-notes

Impacted products

1 product

Vendor	Product	Version
freedesktop.org	libslirp	Affected: 0 , < 4.9.2 (semver)

Date Public

2026-06-24 04:25

Credits

Bruce Chen of STAR Labs SG Pte. Ltd. Shi Weiming of STAR Labs SG Pte. Ltd.

Show details on NVD website

JSON

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              "content": {
                "id": "CVE-2026-9539",
                "options": [
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                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-24T12:39:41.276722Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        "providerMetadata": {
          "dateUpdated": "2026-06-24T12:39:59.831Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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Sightings

Author	Source	Type	Date	Other

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.

Action not permitted

GHSA-4243-HP56-4M7F

CVE-2026-9539 (GCVE-0-2026-9539)

Tags

Sightings

Nomenclature