Vulnerability-Lookup

ubuntu-cve-2026-43970

Vulnerability from osv_ubuntu

Published

2026-05-13 19:17

Modified

2026-05-13 19:17

Summary

Details

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows unauthenticated remote denial of service via memory exhaustion. cow_spdy:inflate/2 in cowlib passes peer-supplied compressed bytes directly to zlib:inflate/2 with no output size bound. The SPDY header compression dictionary (?ZDICT) is public, and zlib compresses long runs of repeated bytes at roughly 1024:1, so a few kilobytes of SPDY frame payload can decompress to gigabytes on the BEAM heap, OOM-killing the node. A single unauthenticated SPDY frame is sufficient to trigger the condition. The parsers for syn_stream, syn_reply, and headers frame types are all affected via cow_spdy:parse_headers/2. This issue affects cowlib from 0.1.0 before 2.16.1.

Severity

8.2 (High)


                    
                      CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-43970	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-43970	REPORT
	https://cna.erlef.org/cves/CVE-2026-43970.html	REPORT
	https://osv.dev/vulnerability/EEF-CVE-2026-43970	REPORT
	https://github.com/ninenines/cowlib/commit/16aad3…	REPORT
	https://github.com/ninenines/cowlib/commit/16aad3…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "erlang-cowlib",
            "binary_version": "1.3.0-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "erlang-cowlib",
        "purl": "pkg:deb/ubuntu/erlang-cowlib@1.3.0-1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "erlang-cowlib",
            "binary_version": "1.3.0-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "erlang-cowlib",
        "purl": "pkg:deb/ubuntu/erlang-cowlib@1.3.0-2?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "erlang-cowlib",
            "binary_version": "1.3.0-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "erlang-cowlib",
        "purl": "pkg:deb/ubuntu/erlang-cowlib@1.3.0-3?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "erlang-cowlib",
            "binary_version": "1.3.0-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "erlang-cowlib",
        "purl": "pkg:deb/ubuntu/erlang-cowlib@1.3.0-3?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "erlang-cowlib",
            "binary_version": "1.3.0-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "erlang-cowlib",
        "purl": "pkg:deb/ubuntu/erlang-cowlib@1.3.0-3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "erlang-cowlib",
            "binary_version": "1.3.0-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "erlang-cowlib",
        "purl": "pkg:deb/ubuntu/erlang-cowlib@1.3.0-3?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "erlang-cowlib",
            "binary_version": "1.3.0-3build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "erlang-cowlib",
        "purl": "pkg:deb/ubuntu/erlang-cowlib@1.3.0-3build1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-3",
        "1.3.0-3build1"
      ]
    }
  ],
  "aliases": [],
  "details": "Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows unauthenticated remote denial of service via memory exhaustion. cow_spdy:inflate/2 in cowlib passes peer-supplied compressed bytes directly to zlib:inflate/2 with no output size bound. The SPDY header compression dictionary (?ZDICT) is public, and zlib compresses long runs of repeated bytes at roughly 1024:1, so a few kilobytes of SPDY frame payload can decompress to gigabytes on the BEAM heap, OOM-killing the node. A single unauthenticated SPDY frame is sufficient to trigger the condition. The parsers for syn_stream, syn_reply, and headers frame types are all affected via cow_spdy:parse_headers/2. This issue affects cowlib from 0.1.0 before 2.16.1.",
  "id": "UBUNTU-CVE-2026-43970",
  "modified": "2026-05-13T19:17:00Z",
  "published": "2026-05-13T19:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-43970"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-43970"
    },
    {
      "type": "REPORT",
      "url": "https://cna.erlef.org/cves/CVE-2026-43970.html"
    },
    {
      "type": "REPORT",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-43970"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/ninenines/cowlib/commit/16aad3fb9f81f5cda4d1706ff0c54237c619c282"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/ninenines/cowlib/commit/16aad3fb9f81f5cda4d1706ff0c54237c619c282"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-43970"
  ]
}

CVE-2026-43970 (GCVE-0-2026-43970)

Vulnerability from cvelistv5 – Published: 2026-05-13 18:43 – Updated: 2026-05-15 04:33

Title

Decompression Bomb in cow_spdy:inflate/2 Allows Memory Exhaustion via Crafted SPDY Frame

Summary

Severity

8.2 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)

Assigner

EEF

References

3 references

URL	Tags
https://cna.erlef.org/cves/CVE-2026-43970.html	relatedthird-party-advisory
https://osv.dev/vulnerability/EEF-CVE-2026-43970	related
https://github.com/ninenines/cowlib/commit/16aad3…	patch

Impacted products

2 products

Vendor	Product	Version
ninenines	cowlib	Affected: 0.1.0 , < 2.16.1 (semver) cpe:2.3:a:ninenines:cowlib::::::::
ninenines	cowlib	Affected: fad5c0049df278cc498b6cdb519b09e845a070a8 , < 16aad3fb9f81f5cda4d1706ff0c54237c619c282 (git) cpe:2.3:a:ninenines:cowlib::::::::

Credits

Peter Ullrich Loïc Hoguin

Show details on NVD website

JSON

To clipboard

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  "containers": {
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                "id": "CVE-2026-43970",
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                  },
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                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-14T12:38:59.086048Z",
                "version": "2.0.3"
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            "cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*"
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            },
            {
              "name": "cow_spdy:inflate/2"
            },
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            },
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            }
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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

ubuntu-cve-2026-43970

Vulnerability from osv_ubuntu

CVE-2026-43970 (GCVE-0-2026-43970)

Tags

Sightings

Nomenclature