CVE-2026-43009: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-c84q-5rwr-h9h9
CVSS 7.8
CWE-682
Published
Advisory Summary

CVE-2026-43009 is a HIGH (CVSS 7.8) security vulnerability vulnerability (CWE-682: Incorrect Calculation) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-43009 at a Glance

CVE Identifier CVE-2026-43009
GHSA Identifier GHSA-c84q-5rwr-h9h9
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-682: Incorrect Calculation
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.8

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

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
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-2026-43009

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-2026-43009, 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 CWE-682: Incorrect Calculation, where the product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management. 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: bpf: Fix incorrect pruning due to atomic fetch precision tracking When backtrack_insn encounters a BPF_STX instruction with BPF_ATOMIC and BPF_FETCH, the src register (or r0 for BPF_CMPXCHG) also acts as a destination, thus receiving the old value from the memory location. The current backtracking logic does not account for this. It treats atomic fetch operations the same as regular stores where the src register is only an input. This leads the backtrack_insn to fail to propagate precision to the stack location, which is then not marked as precise! Later, the verifier's path pruning can incorrectly consider two states equivalent when they differ in terms of stack state. Meaning, two branches can be treated as equivalent and thus get pruned when they should not be seen as such. Fix it as follows: Extend the BPF_LDX handling in backtrack_insn to also cover atomic fetch operations via is_atomic_fetch_insn() helper. When the fetch dst register is being tracked for precision, clear it, and propagate precision over to the stack slot. For non-stack memory, the precision walk stops at the atomic instruction, same as regular BPF_LDX. This covers all fetch variants. Before: 0: (b7) r1 = 8 ; R1=8 1: (7b) *(u64 *)(r10 -8) = r1 ; R1=8 R10=fp0 fp-8=8 2: (b7) r2 = 0 ; R2=0 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2) ; R2=8 R10=fp0 fp-8=mmmmmmmm 4: (bf) r3 = r10 ; R3=fp0 R10=fp0 5: (0f) r3 += r2 mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1 mark_precise: frame0: regs=r2 stack= before 4: (bf) r3 = r10 mark_precise: frame0: regs=r2 stack= before 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2) mark_precise: frame0: regs=r2 stack= before 2: (b7) r2 = 0 6: R2=8 R3=fp8 6: (b7) r0 = 0 ; R0=0 7: (95) exit After: 0: (b7) r1 = 8 ; R1=8 1: (7b) *(u64 *)(r10 -8) = r1 ; R1=8 R10=fp0 fp-8=8 2: (b7) r2 = 0 ; R2=0 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2) ; R2=8 R10=fp0 fp-8=mmmmmmmm 4: (bf) r3 = r10 ; R3=fp0 R10=fp0 5: (0f) r3 += r2 mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1 mark_precise: frame0: regs=r2 stack= before 4: (bf) r3 = r10 mark_precise: frame0: regs=r2 stack= before 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2) mark_precise: frame0: regs= stack=-8 before 2: (b7) r2 = 0 mark_precise: frame0: regs= stack=-8 before 1: (7b) *(u64 *)(r10 -8) = r1 mark_precise: frame0: regs=r1 stack= before 0: (b7) r1 = 8 6: R2=8 R3=fp8 6: (b7) r0 = 0 ; R0=0 7: (95) exit

References

Frequently Asked Questions

What is CVE-2026-43009?
CVE-2026-43009 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-682: Incorrect Calculation.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-43009?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-43009?
CVE-2026-43009 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-43009?
CVE-2026-43009 is classified under CWE-682: Incorrect Calculation (The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.).
How can I check Maven dependencies for CVE-2026-43009?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c84q-5rwr-h9h9",
  "modified" : "2026-09-07T18:31:31Z",
  "published" : "2026-05-01T15:30:36Z",
  "aliases" : [ "CVE-2026-43009" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix incorrect pruning due to atomic fetch precision tracking\n\nWhen backtrack_insn encounters a BPF_STX instruction with BPF_ATOMIC\nand BPF_FETCH, the src register (or r0 for BPF_CMPXCHG) also acts as\na destination, thus receiving the old value from the memory location.\n\nThe current backtracking logic does not account for this. It treats\natomic fetch operations the same as regular stores where the src\nregister is only an input. This leads the backtrack_insn to fail to\npropagate precision to the stack location, which is then not marked\nas precise!\n\nLater, the verifier's path pruning can incorrectly consider two states\nequivalent when they differ in terms of stack state. Meaning, two\nbranches can be treated as equivalent and thus get pruned when they\nshould not be seen as such.\n\nFix it as follows: Extend the BPF_LDX handling in backtrack_insn to\nalso cover atomic fetch operations via is_atomic_fetch_insn() helper.\nWhen the fetch dst register is being tracked for precision, clear it,\nand propagate precision over to the stack slot. For non-stack memory,\nthe precision walk stops at the atomic instruction, same as regular\nBPF_LDX. This covers all fetch variants.\n\nBefore:\n\n  0: (b7) r1 = 8                        ; R1=8\n  1: (7b) *(u64 *)(r10 -8) = r1         ; R1=8 R10=fp0 fp-8=8\n  2: (b7) r2 = 0                        ; R2=0\n  3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2)          ; R2=8 R10=fp0 fp-8=mmmmmmmm\n  4: (bf) r3 = r10                      ; R3=fp0 R10=fp0\n  5: (0f) r3 += r2\n  mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1\n  mark_precise: frame0: regs=r2 stack= before 4: (bf) r3 = r10\n  mark_precise: frame0: regs=r2 stack= before 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2)\n  mark_precise: frame0: regs=r2 stack= before 2: (b7) r2 = 0\n  6: R2=8 R3=fp8\n  6: (b7) r0 = 0                        ; R0=0\n  7: (95) exit\n\nAfter:\n\n  0: (b7) r1 = 8                        ; R1=8\n  1: (7b) *(u64 *)(r10 -8) = r1         ; R1=8 R10=fp0 fp-8=8\n  2: (b7) r2 = 0                        ; R2=0\n  3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2)          ; R2=8 R10=fp0 fp-8=mmmmmmmm\n  4: (bf) r3 = r10                      ; R3=fp0 R10=fp0\n  5: (0f) r3 += r2\n  mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1\n  mark_precise: frame0: regs=r2 stack= before 4: (bf) r3 = r10\n  mark_precise: frame0: regs=r2 stack= before 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2)\n  mark_precise: frame0: regs= stack=-8 before 2: (b7) r2 = 0\n  mark_precise: frame0: regs= stack=-8 before 1: (7b) *(u64 *)(r10 -8) = r1\n  mark_precise: frame0: regs=r1 stack= before 0: (b7) r1 = 8\n  6: R2=8 R3=fp8\n  6: (b7) r0 = 0                        ; R0=0\n  7: (95) exit",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-43009"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/179ee84a89114b854ac2dd1d293633a7f6c8dac1"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/7ffbe45b1d227e24659998a91cfd4c27af457e71"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ea150ffa9fc9f78c5cf22e1f7b06b6d016b1017c"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-682" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-05-01T15:16:44Z"
  }
}