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In the Linux kernel, the following vulnerability has been...

Moderate severity Unreviewed Published Sep 22, 2025 to the GitHub Advisory Database • Updated Jan 20, 2026

Package

No package listed— Suggest a package

Affected versions

Unknown

Patched versions

Unknown

Description

In the Linux kernel, the following vulnerability has been resolved:

ppp: fix memory leak in pad_compress_skb

If alloc_skb() fails in pad_compress_skb(), it returns NULL without
releasing the old skb. The caller does:

skb = pad_compress_skb(ppp, skb);
if (!skb)
    goto drop;

drop:
kfree_skb(skb);

When pad_compress_skb() returns NULL, the reference to the old skb is
lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak.

Align pad_compress_skb() semantics with realloc(): only free the old
skb if allocation and compression succeed. At the call site, use the
new_skb variable so the original skb is not lost when pad_compress_skb()
fails.

References

Published by the National Vulnerability Database Sep 19, 2025
Published to the GitHub Advisory Database Sep 22, 2025
Last updated Jan 20, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(3rd percentile)

Weaknesses

Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse. Learn more on MITRE.

CVE ID

CVE-2025-39847

GHSA ID

GHSA-9f6g-j2jq-6w3f

Source code

No known source code

Dependabot alerts are not supported on this advisory because it does not have a package from a supported ecosystem with an affected and fixed version.

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