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NVD / CVE Program· CNA Linux

CVE-2025-68262: crypto: zstd - fix double-free in per-CPU stream cleanup

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
  • Fixed version: Linux Linux 48bc9da3c97c15f1ea24934bcb3b736acd30163d, dc0f4509b0ed5d82bef78e058db0ac4df04d0695, e983feaa79de1e46c9087fb9f02fedb0e5397ce6.

Low priority for now. Upgrade to Linux Linux 48bc9da3c97c15f1ea24934bcb3b736acd30163d, dc0f4509b0ed5d82bef78e058db0ac4df04d0695, e983feaa79de1e46c9087fb9f02fedb0e5397ce6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: crypto: zstd - fix double-free in per-CPU stream cleanup The crypto/zstd module has a double-free bug that occurs when multiple tfms are allocated and freed. The issue happens because zstd_streams (per-CPU contexts) are freed in zstd_exit() during every tfm destruction, rather than being managed at the module level. When multiple tfms exist, each tfm exit attempts to free the same shared per-CPU streams, resulting in a double-free. This leads to a stack trace similar to: BUG: Bad page state in process kworker/u16:1 pfn:106fd93 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106fd93 flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 0017ffffc0000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: nonzero entire_mapcount Modules linked in: ... CPU: 3 UID: 0 PID: 2506 Comm: kworker/u16:1 Kdump: loaded Tainted: G B Hardware name: ... Workqueue: btrfs-delalloc btrfs_work_helper Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 bad_page+0x71/0xd0 free_unref_page_prepare+0x24e/0x490 free_unref_page+0x60/0x170 crypto_acomp_free_streams+0x5d/0xc0 crypto_acomp_exit_tfm+0x23/0x50 crypto_destroy_tfm+0x60/0xc0 ... Change the lifecycle management of zstd_streams to free the streams only once during module cleanup.

—No exploit Fix available
Published
Dec 16, 2025
Updated
Oct 14, 2026
EPSS
0.1% · 7th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.17affected
    • f5ad93ffb54119a8dc5e18f070624d4ead586969 and later · before dc0f4509b0ed5d82bef78e058db0ac4df04d0695affected · git
    • f5ad93ffb54119a8dc5e18f070624d4ead586969 and later · before e983feaa79de1e46c9087fb9f02fedb0e5397ce6affected · git
    • f5ad93ffb54119a8dc5e18f070624d4ead586969 and later · before 48bc9da3c97c15f1ea24934bcb3b736acd30163daffected · git
    • before 6.17not affected · semver
    • 6.17.12 and later · up to and including 6.17.*not affected · semver
    • 6.18.1 and later · up to and including 6.18.*not affected · semver
    • 6.19 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:14linuxbefore 6.17.12-16.17.12-1
openSUSE:Tumbleweedkernel-sourcebefore 6.18.2-1.16.18.2-1.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2025-68260Dec 16, 2025 · rust_binder: fix race condition on death_list
    31Monitor
  • ← EarlierCVE-2025-68261Dec 16, 2025 · ext4: add i_data_sem protection in ext4_destroy_inline_data_nolock()
    30Monitor
  • Later →CVE-2025-68263Dec 16, 2025 · ksmbd: ipc: fix use-after-free in ipc_msg_send_request
    39Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux48bc9da3c97c15f1ea24934bcb3b736acd30163dVendor (CNA)
Linux Linuxdc0f4509b0ed5d82bef78e058db0ac4df04d0695Vendor (CNA)
Linux Linuxe983feaa79de1e46c9087fb9f02fedb0e5397ce6Vendor (CNA)
debian:linux6.17.12-1 · Debian:14Package registry (OSV)
opensuse:kernel-source6.18.2-1.1 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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