CVE-2026-89551: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-7gqj-379q-cvhq
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CVSS 9.8
Published
Advisory Summary

CVE-2026-89551 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-2026-89551 at a Glance

CVE Identifier CVE-2026-89551
GHSA Identifier GHSA-7gqj-379q-cvhq
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-2026-89551

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-2026-89551, 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: SUNRPC: xdr_buf_trim: clamp buf->len to avoid underflow xdr_buf_trim() trims `len` bytes from the tail of an xdr_buf by walking the tail, pages, and head iovecs. Each per-section step uses min_t() so it never removes more bytes than that section holds, but the final accounting at the fix_len label subtracts the total bytes actually consumed from buf->len without any clamp: fix_len: buf->len -= (len - trim); When the caller has set buf->len to a value smaller than the sum of the iov_lens, (len - trim) can exceed buf->len and the unsigned subtraction wraps to near UINT_MAX. gss_krb5_unwrap_v2() reaches xdr_buf_trim() in exactly that state: buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip; buf->len = len - (GSS_KRB5_TOK_HDR_LEN + headskip); xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip); buf->len is a small wire-derived value while the iov_lens are at page scale, so the per-section loops legitimately consume far more bytes than buf->len records. The wrapped buf->len then propagates as the authoritative stream bound into every downstream XDR decoder. Fix by clamping the decrement so buf->len bottoms out at zero: buf->len -= min_t(unsigned int, buf->len, len - trim); On the normal path where the iov_lens sum to buf->len, (len - trim) is always <= buf->len and the result is identical to before. No callers change behavior outside the underflow case.

References

NVD — CVE-2026-89551 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89551
git.kernel.org/stable/c/3f491306dc... WEB
https://git.kernel.org/stable/c/3f491306dcb673ff5e78e1044ba450c58978774e
git.kernel.org/stable/c/4bf59cb0ea... WEB
https://git.kernel.org/stable/c/4bf59cb0ea5b0ddfbc46a1dc2fa78fc8b9986ce4
git.kernel.org/stable/c/85e9602650... WEB
https://git.kernel.org/stable/c/85e9602650e9df07190abe817cee3b4d9bc3df17
git.kernel.org/stable/c/a3d77bcd97... WEB
https://git.kernel.org/stable/c/a3d77bcd974b8625d16bddf448cb3a1b5e37049c
git.kernel.org/stable/c/a924ac4c78... WEB
https://git.kernel.org/stable/c/a924ac4c78afab71bf82641afa3b62e0c4a8b55e
git.kernel.org/stable/c/ad0cce80d4... WEB
https://git.kernel.org/stable/c/ad0cce80d4af2f74674e8b635d97aa3880e83da8
git.kernel.org/stable/c/e6267cccd7... WEB
https://git.kernel.org/stable/c/e6267cccd7b05cc514e57f2160aa8db85f5c2701
git.kernel.org/stable/c/fa16bbe987... WEB
https://git.kernel.org/stable/c/fa16bbe987b47e771e52eeb1b4540f18d92496ac

Frequently Asked Questions

What is CVE-2026-89551?
CVE-2026-89551 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-2026-89551?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-89551?
CVE-2026-89551 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-2026-89551?
CVE-2026-89551 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89551?
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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  "schema_version" : "1.4.0",
  "id" : "GHSA-7gqj-379q-cvhq",
  "modified" : "2026-09-14T15:32:28Z",
  "published" : "2026-09-11T21:31:31Z",
  "aliases" : [ "CVE-2026-89551" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: xdr_buf_trim: clamp buf->len to avoid underflow\n\nxdr_buf_trim() trims `len` bytes from the tail of an xdr_buf by\nwalking the tail, pages, and head iovecs.  Each per-section step\nuses min_t() so it never removes more bytes than that section\nholds, but the final accounting at the fix_len label subtracts the\ntotal bytes actually consumed from buf->len without any clamp:\n\n    fix_len:\n            buf->len -= (len - trim);\n\nWhen the caller has set buf->len to a value smaller than the sum\nof the iov_lens, (len - trim) can exceed buf->len and the unsigned\nsubtraction wraps to near UINT_MAX.  gss_krb5_unwrap_v2() reaches\nxdr_buf_trim() in exactly that state:\n\n    buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;\n    buf->len = len - (GSS_KRB5_TOK_HDR_LEN + headskip);\n    xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip);\n\nbuf->len is a small wire-derived value while the iov_lens are at\npage scale, so the per-section loops legitimately consume far more\nbytes than buf->len records.  The wrapped buf->len then propagates\nas the authoritative stream bound into every downstream XDR\ndecoder.\n\nFix by clamping the decrement so buf->len bottoms out at zero:\n\n    buf->len -= min_t(unsigned int, buf->len, len - trim);\n\nOn the normal path where the iov_lens sum to buf->len, (len - trim)\nis always <= buf->len and the result is identical to before.  No\ncallers change behavior outside the underflow case.",
  "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-2026-89551"
  }, {
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    "url" : "https://git.kernel.org/stable/c/3f491306dcb673ff5e78e1044ba450c58978774e"
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    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/4bf59cb0ea5b0ddfbc46a1dc2fa78fc8b9986ce4"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/85e9602650e9df07190abe817cee3b4d9bc3df17"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/a3d77bcd974b8625d16bddf448cb3a1b5e37049c"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/a924ac4c78afab71bf82641afa3b62e0c4a8b55e"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ad0cce80d4af2f74674e8b635d97aa3880e83da8"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e6267cccd7b05cc514e57f2160aa8db85f5c2701"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/fa16bbe987b47e771e52eeb1b4540f18d92496ac"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-11T20:19:38Z"
  }
}