CVE-2026-63831: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-3745-g9hm-6m5f
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CVSS 8.8
CWE-416
Published
Advisory Summary

CVE-2026-63831 is a HIGH (CVSS 8.8) security vulnerability vulnerability (CWE-416: Use After Free) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product reuses or references memory after it has been freed. at some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-63831 at a Glance

CVE Identifier CVE-2026-63831
GHSA Identifier GHSA-3745-g9hm-6m5f
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-416: Use After Free
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.8

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

Attack Vector Adjacent (AV:A)
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-2026-63831

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-2026-63831, 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-416: Use After Free, where the product reuses or references memory after it has been freed. at some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. 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: mac802154: llsec: add skb_cow_data() before in-place crypto llsec_do_encrypt_unauth(), llsec_do_encrypt_auth(), llsec_do_decrypt_unauth(), and llsec_do_decrypt_auth() all perform in-place cryptographic transformations on skb data. They build a scatterlist with sg_init_one() pointing into the skb's linear data area and then pass the same scatterlist as both src and dst to the crypto API (e.g. crypto_skcipher_encrypt/decrypt, crypto_aead_encrypt/decrypt). On the RX path, __ieee802154_rx_handle_packet() clones the received skb before handing it to each subscriber via ieee802154_subif_frame(). The cloned skb shares the same underlying data buffer via reference counting. When llsec_do_decrypt() subsequently modifies this shared buffer in place, it corrupts data that other clones -- potentially belonging to other sockets or subsystems -- still reference. On the TX path, similar data sharing can occur when an skb's head has been cloned (skb_cloned() returns true). The fix is to call skb_cow_data() before performing any in-place crypto operation. skb_cow_data() ensures that the skb's data area is not shared: if the skb head is cloned or the data spans multiple fragments, it copies the data into a private buffer that can be safely modified in place. This is the same pattern used by: - ESP (net/ipv4/esp4.c, net/ipv6/esp6.c) - MACsec (drivers/net/macsec.c) - WireGuard (drivers/net/wireguard/receive.c) - TIPC (net/tipc/crypto.c) Without this guard, in-place crypto on shared skb data leads to: - Silent data corruption of other skb clones - Use-after-free when the crypto API scatterwalk writes through a page that has already been freed by another clone's kfree_skb() - Kernel crashes under concurrent 802.15.4 traffic with security enabled (KASAN/KMSAN reports slab-use-after-free) Found by 0sec (https://0sec.ai) using automated source analysis.

References

NVD — CVE-2026-63831 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63831
git.kernel.org/stable/c/3a2b378b3a... WEB
https://git.kernel.org/stable/c/3a2b378b3a9ca75d3518d879148d2ad25b5714a9
git.kernel.org/stable/c/7a831bcd04... WEB
https://git.kernel.org/stable/c/7a831bcd0486788283ef35e396d4282ee01bb0d5
git.kernel.org/stable/c/84a04eb5b2... WEB
https://git.kernel.org/stable/c/84a04eb5b210643bd67aab81ff805d32f62aa865
git.kernel.org/stable/c/86d531337e... WEB
https://git.kernel.org/stable/c/86d531337ea1ba02d9f2bc830d07c683d9bfaade
git.kernel.org/stable/c/993fd674fe... WEB
https://git.kernel.org/stable/c/993fd674fe85d114e6a8d3963033d4fbbc2170a8
git.kernel.org/stable/c/bd968bdd56... WEB
https://git.kernel.org/stable/c/bd968bdd568beacfdf98ec537a87527e85f1d0cf
git.kernel.org/stable/c/e28e7fd34c... WEB
https://git.kernel.org/stable/c/e28e7fd34c449028325322a3f5127b92594b7396
git.kernel.org/stable/c/ff976ef7c3... WEB
https://git.kernel.org/stable/c/ff976ef7c39199ebff33c18034636595016db9f0

Frequently Asked Questions

What is CVE-2026-63831?
CVE-2026-63831 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-416: Use After Free.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-63831?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-63831?
CVE-2026-63831 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-63831?
CVE-2026-63831 is classified under CWE-416: Use After Free (The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.).
How can I check Maven dependencies for CVE-2026-63831?
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-3745-g9hm-6m5f",
  "modified" : "2026-07-20T15:31:47Z",
  "published" : "2026-07-19T12:30:24Z",
  "aliases" : [ "CVE-2026-63831" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nmac802154: llsec: add skb_cow_data() before in-place crypto\n\nllsec_do_encrypt_unauth(), llsec_do_encrypt_auth(),\nllsec_do_decrypt_unauth(), and llsec_do_decrypt_auth() all perform\nin-place cryptographic transformations on skb data.  They build a\nscatterlist with sg_init_one() pointing into the skb's linear data area\nand then pass the same scatterlist as both src and dst to the crypto API\n(e.g. crypto_skcipher_encrypt/decrypt, crypto_aead_encrypt/decrypt).\n\nOn the RX path, __ieee802154_rx_handle_packet() clones the received skb\nbefore handing it to each subscriber via ieee802154_subif_frame().  The\ncloned skb shares the same underlying data buffer via reference\ncounting.  When llsec_do_decrypt() subsequently modifies this shared\nbuffer in place, it corrupts data that other clones -- potentially\nbelonging to other sockets or subsystems -- still reference.\n\nOn the TX path, similar data sharing can occur when an skb's head has\nbeen cloned (skb_cloned() returns true).\n\nThe fix is to call skb_cow_data() before performing any in-place crypto\noperation.  skb_cow_data() ensures that the skb's data area is not\nshared: if the skb head is cloned or the data spans multiple fragments,\nit copies the data into a private buffer that can be safely modified in\nplace.  This is the same pattern used by:\n\n  - ESP (net/ipv4/esp4.c, net/ipv6/esp6.c)\n  - MACsec (drivers/net/macsec.c)\n  - WireGuard (drivers/net/wireguard/receive.c)\n  - TIPC (net/tipc/crypto.c)\n\nWithout this guard, in-place crypto on shared skb data leads to:\n  - Silent data corruption of other skb clones\n  - Use-after-free when the crypto API scatterwalk writes through a\n    page that has already been freed by another clone's kfree_skb()\n  - Kernel crashes under concurrent 802.15.4 traffic with security\n    enabled (KASAN/KMSAN reports slab-use-after-free)\n\nFound by 0sec (https://0sec.ai) using automated source analysis.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
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    "url" : "https://git.kernel.org/stable/c/86d531337ea1ba02d9f2bc830d07c683d9bfaade"
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    "url" : "https://git.kernel.org/stable/c/ff976ef7c39199ebff33c18034636595016db9f0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-416" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-19T12:16:56Z"
  }
}