CVE-2026-80587: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-hrrc-rjw8-mj44
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CVSS 9.8
Published
Advisory Summary

CVE-2026-80587 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-80587 at a Glance

CVE Identifier CVE-2026-80587
GHSA Identifier GHSA-hrrc-rjw8-mj44
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-80587

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-80587, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In the Linux kernel, the following vulnerability has been resolved: mptcp: avoid combining some incoming suboptions Some MPTCP suboptions are mutually exclusive according to the RFC8684, but also because in different places, the code doesn't expect some combinations to be present. That's specially true for suboptions that would be present twice, but with different attributes. The new restrictions are the same as the ones applied on the output side, with mptcp_write_options. The same rules can be reused with a small fix: an MP_FASTCLOSE can be used with a DSS when the sender picks this option [1], which is not the case on Linux. Here are the rules: Which options can be used together? X: mutually exclusive O: often used together C: can be used together in some cases P: could be used together but we prefer not to (optimisations) | Opt: | MPC | MPJ | DSS | ADD | RM | PRIO | FAIL | FC | |------|------|------|------|------|------|------|------|------| | MPC |------|------|------|------|------|------|------|------| | MPJ | X |------|------|------|------|------|------|------| | DSS | X | X |------|------|------|------|------|------| | ADD | X | X | P |------|------|------|------|------| | RM | C | C | C | P |------|------|------|------| | PRIO | X | C | C | C | C |------|------|------| | FAIL | X | X | C | X | X | X |------|------| | FC | X | X | P | X | X | X | X |------| | RST | X | X | X | X | X | X | O | O | |------|------|------|------|------|------|------|------|------| The only difference is with the 'P': another stack could send and ADD_ADDR with other suboptions (DSS, RM_ADDR), and this should be allowed. A few points of attention: - In theory, an MP_CAPABLE could be used with a RM_ADDR, but there is no reason to add it with a SYN. Note that even with a 4th ACK, it doesn't seem to be useful, except when IDs are known in advance via another channel. Better not to break that. - Now, combining both an MP_CAPABLE and an MP_JOIN will no longer result to a reject of the two options, but only the second suboption is ignored. That seems OK to do that for this unexpected error. At least now all inconsistent combinations are handled the same way. This could change later in next. This also means the explicit checks for having both MPC + MPJ in subflow.c will now be unreachable. That's fine, they will be removed in a follow-up patch. - In case of conflicting combinations, the extra suboption(s) is/are ignored: having such combinations either means the remote peer is buggy, or is evil. The simplest action is then taken in this case: stop processing the current suboption. - In mp_opt->suboptions, there is also a bit reserved to the checksum, which can be used in an MP_CAPABLE and a DSS. Each time a DSS option can be used in parallel with another option, the checksum can be set, so the verification is combined into a new OPTIONS_MPTCP_DSS macro. - An MP_CAPABLE ACK can carry a Data-Level Length, and an optional Checksum: they are the same as the ones found in a DSS, because a DSS cannot be used in parallel to an MP_CAPABLE. Similarly, even if there is room, a DSS cannot be used with an MP_JOIN.

References

NVD — CVE-2026-80587 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-80587
git.kernel.org/stable/c/099bfcbd0c... WEB
https://git.kernel.org/stable/c/099bfcbd0c16ae9b50aba2a1bea033e63f895da7
git.kernel.org/stable/c/0e2210af43... WEB
https://git.kernel.org/stable/c/0e2210af439755a2af352eea4178261dcf61742e
git.kernel.org/stable/c/6bab907292... WEB
https://git.kernel.org/stable/c/6bab907292155513af397a12ccb488acbfc30d79
git.kernel.org/stable/c/a04dcc7849... WEB
https://git.kernel.org/stable/c/a04dcc784959e4702048785d87e0d029bd2fbdcb
git.kernel.org/stable/c/b6ee361524... WEB
https://git.kernel.org/stable/c/b6ee361524641f57b2e2363f7737f20e17f67827
git.kernel.org/stable/c/dc1d8d3eb3... WEB
https://git.kernel.org/stable/c/dc1d8d3eb345c616fbe922a010fa391c72c54d52

Frequently Asked Questions

What is CVE-2026-80587?
CVE-2026-80587 is a security vulnerability in Software classified as a security vulnerability vulnerability under General Security Weakness.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-80587?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-80587?
CVE-2026-80587 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-80587?
CVE-2026-80587 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-80587?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
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  "id" : "GHSA-hrrc-rjw8-mj44",
  "modified" : "2026-08-27T15:31:33Z",
  "published" : "2026-08-27T06:31:33Z",
  "aliases" : [ "CVE-2026-80587" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: avoid combining some incoming suboptions\n\nSome MPTCP suboptions are mutually exclusive according to the RFC8684,\nbut also because in different places, the code doesn't expect some\ncombinations to be present. That's specially true for suboptions that\nwould be present twice, but with different attributes.\n\nThe new restrictions are the same as the ones applied on the output\nside, with mptcp_write_options. The same rules can be reused with a\nsmall fix: an MP_FASTCLOSE can be used with a DSS when the sender picks\nthis option [1], which is not the case on Linux. Here are the rules:\n\n  Which options can be used together?\n\n  X: mutually exclusive\n  O: often used together\n  C: can be used together in some cases\n  P: could be used together but we prefer not to (optimisations)\n\n  | Opt: | MPC  | MPJ  | DSS  | ADD  |  RM  | PRIO | FAIL |  FC  |\n  |------|------|------|------|------|------|------|------|------|\n  | MPC  |------|------|------|------|------|------|------|------|\n  | MPJ  |  X   |------|------|------|------|------|------|------|\n  | DSS  |  X   |  X   |------|------|------|------|------|------|\n  | ADD  |  X   |  X   |  P   |------|------|------|------|------|\n  | RM   |  C   |  C   |  C   |  P   |------|------|------|------|\n  | PRIO |  X   |  C   |  C   |  C   |  C   |------|------|------|\n  | FAIL |  X   |  X   |  C   |  X   |  X   |  X   |------|------|\n  | FC   |  X   |  X   |  P   |  X   |  X   |  X   |  X   |------|\n  | RST  |  X   |  X   |  X   |  X   |  X   |  X   |  O   |  O   |\n  |------|------|------|------|------|------|------|------|------|\n\nThe only difference is with the 'P': another stack could send and\nADD_ADDR with other suboptions (DSS, RM_ADDR), and this should be\nallowed.\n\nA few points of attention:\n\n - In theory, an MP_CAPABLE could be used with a RM_ADDR, but there is\n   no reason to add it with a SYN. Note that even with a 4th ACK, it\n   doesn't seem to be useful, except when IDs are known in advance via\n   another channel. Better not to break that.\n\n - Now, combining both an MP_CAPABLE and an MP_JOIN will no longer\n   result to a reject of the two options, but only the second suboption\n   is ignored. That seems OK to do that for this unexpected error. At\n   least now all inconsistent combinations are handled the same way.\n   This could change later in next. This also means the explicit checks\n   for having both MPC + MPJ in subflow.c will now be unreachable.\n   That's fine, they will be removed in a follow-up patch.\n\n - In case of conflicting combinations, the extra suboption(s) is/are\n   ignored: having such combinations either means the remote peer is\n   buggy, or is evil. The simplest action is then taken in this case:\n   stop processing the current suboption.\n\n - In mp_opt->suboptions, there is also a bit reserved to the checksum,\n   which can be used in an MP_CAPABLE and a DSS. Each time a DSS option\n   can be used in parallel with another option, the checksum can be set,\n   so the verification is combined into a new OPTIONS_MPTCP_DSS macro.\n\n - An MP_CAPABLE ACK can carry a Data-Level Length, and an optional\n   Checksum: they are the same as the ones found in a DSS, because a DSS\n   cannot be used in parallel to an MP_CAPABLE. Similarly, even if there\n   is room, a DSS cannot be used with an MP_JOIN.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-80587"
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    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/099bfcbd0c16ae9b50aba2a1bea033e63f895da7"
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    "url" : "https://git.kernel.org/stable/c/6bab907292155513af397a12ccb488acbfc30d79"
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    "url" : "https://git.kernel.org/stable/c/a04dcc784959e4702048785d87e0d029bd2fbdcb"
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    "url" : "https://git.kernel.org/stable/c/b6ee361524641f57b2e2363f7737f20e17f67827"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/dc1d8d3eb345c616fbe922a010fa391c72c54d52"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-26T15:17:15Z"
  }
}