FKIE_CVE-2026-77680

Vulnerability from fkie_nvd - Published: 2026-08-25 21:17 - Updated: 2026-08-28 21:17
Severity
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Summary
An algorithmic complexity flaw exists in libsoup's HTTP Range header processing that persists after the CVE-2025-32907 fix. CVE-2025-32907 addressed memory amplification when a client repeated the same range many times in a single Range header. Commit 9bb92f7a corrected merge correctness in soup_message_headers_get_ranges_internal() in libsoup/soup-message-headers.c, but the coalescing loop still removes merged ranges using g_array_remove_index() for each coalesced element. Because GArray is contiguous, each mid-array removal performs an O(N) memmove. When many identical satisfiable ranges are supplied (for example bytes=0-0 repeated thousands of times), the loop performs O(N²) work coalescing them into a single range. The vulnerable path is reachable server-side from handle_partial_get() in libsoup/server/http1/soup-server-message-io-http1.c when a SoupServer handler returns HTTP 200 with a non-empty body. No authentication is required. The number of ranges is bounded only by the maximum request header size (~100 KiB), allowing roughly 25,000 ranges per request. Reporter measurements on libsoup HEAD containing the CVE-2025-32907 fix show ~90 ms single-core CPU per such request at the wire maximum, blocking the server's event loop for that duration. This is a CPU exhaustion / availability issue only. No memory corruption or information disclosure occurs. Affected: libsoup versions containing the CVE-2025-32907 fix but not merge request !550. Fixed upstream: MR !550 merged 2026-08-20, replacing per-element removal with O(N) in-place compaction and rejecting Range headers requesting more than 200 ranges. Upstream report: https://gitlab.gnome.org/GNOME/libsoup/-/issues/538 Related: CVE-2025-32907
References
secalert@redhat.comhttps://access.redhat.com/security/cve/CVE-2025-32907
secalert@redhat.comhttps://access.redhat.com/security/cve/CVE-2026-77680
secalert@redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=2520892
secalert@redhat.comhttps://gitlab.gnome.org/GNOME/libsoup/-/issues/538
secalert@redhat.comhttps://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/550
134c704f-9b21-4f2e-91b3-4a467353bcc0https://gitlab.gnome.org/GNOME/libsoup/-/issues/538
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10"
          ],
          "defaultStatus": "affected",
          "packageName": "libsoup3",
          "product": "Red Hat Enterprise Linux 10",
          "vendor": "Red Hat"
        }
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An algorithmic complexity flaw exists in libsoup\u0027s HTTP Range header processing that persists after the CVE-2025-32907 fix.\n\nCVE-2025-32907 addressed memory amplification when a client repeated the same range many times in a single Range header. Commit 9bb92f7a corrected merge correctness in soup_message_headers_get_ranges_internal() in libsoup/soup-message-headers.c, but the coalescing loop still removes merged ranges using g_array_remove_index() for each coalesced element. Because GArray is contiguous, each mid-array removal performs an O(N) memmove. When many identical satisfiable ranges are supplied (for example bytes=0-0 repeated thousands of times), the loop performs O(N\u00b2) work coalescing them into a single range.\n\nThe vulnerable path is reachable server-side from handle_partial_get() in libsoup/server/http1/soup-server-message-io-http1.c when a SoupServer handler returns HTTP 200 with a non-empty body. No authentication is required. The number of ranges is bounded only by the maximum request header size (~100 KiB), allowing roughly 25,000 ranges per request. Reporter measurements on libsoup HEAD containing the CVE-2025-32907 fix show ~90 ms single-core CPU per such request at the wire maximum, blocking the server\u0027s event loop for that duration.\n\nThis is a CPU exhaustion / availability issue only. No memory corruption or information disclosure occurs.\n\nAffected: libsoup versions containing the CVE-2025-32907 fix but not merge request !550.\nFixed upstream: MR !550 merged 2026-08-20, replacing per-element removal with O(N) in-place compaction and rejecting Range headers requesting more than 200 ranges.\nUpstream report: https://gitlab.gnome.org/GNOME/libsoup/-/issues/538\nRelated: CVE-2025-32907"
    }
  ],
  "id": "CVE-2026-77680",
  "lastModified": "2026-08-28T21:17:10.720",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "secalert@redhat.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-77680",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-26T12:38:58.296657Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-25T21:17:46.243",
  "references": [
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/security/cve/CVE-2025-32907"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/security/cve/CVE-2026-77680"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2520892"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://gitlab.gnome.org/GNOME/libsoup/-/issues/538"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/550"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://gitlab.gnome.org/GNOME/libsoup/-/issues/538"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-407"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Secondary"
    }
  ]
}



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