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Vulnerabilities

Vulnerability · CVE-2025-38463

In the Linux kernel, the following vulnerability has been resolved: tcp: Correct signedness in skb remaining space calculation Syzkaller reported a bug [1] where sk->sk_forward_all

Published Jul 25, 2025 · catalog updated Aug 5, 2026 · Linux Linux

Check this week

CVE-2025-38463 is not in CISA KEV. FIRST estimates a 18.00% chance of exploitation in the next 30 days. Check whether you run Linux Linux.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
18.00%
Remediation
Version ranges on file
Affected products
vendor Linux Linux 270a1c3de47e49dd2fc18f48e46b101e48050e78 <9f164fa6bb09fbcc60fa5c3ff551ce9eec1befd7

In the Linux kernel, the following vulnerability has been resolved: tcp: Correct signedness in skb remaining space calculation Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow. When we send data, if an skb exists at the tail of the write queue, the kernel will attempt to append the new data to that skb. However, the code that checks for available space in the skb is flawed: ''' copy = size_goal - skb->len ''' The types of the variables involved are: ''' copy: ssize_t (s64 on 64-bit systems) size_goal: int skb->len: unsigned int ''' Due to C's type promotion rules, the signe

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

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  • vendor Linux Linux 270a1c3de47e49dd2fc18f48e46b101e48050e78 <9f164fa6bb09fbcc60fa5c3ff551ce9eec1befd7270a1c3de47e49dd2fc18f48e46b101e48050e78 <9f164fa6bb09fbcc60fa5c3ff551ce9eec1befd7

How to fix CVE-2025-38463

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2025-38463 is not in CISA KEV. FIRST estimates a 18.00% chance of exploitation in the next 30 days. Check whether you run Linux Linux.

Which versions are affected?

Compare what you have installed with Linux Linux 270a1c3de47e49dd2fc18f48e46b101e48050e78 <9f164fa6bb09fbcc60fa5c3ff551ce9eec1befd7 270a1c3de47e49dd2fc18f48e46b101e48050e78 <9f164fa6bb09fbcc60fa5c3ff551ce9eec1befd7. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 18.00%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 25, 2025 · EUVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: tcp: Correct signedness in skb remaining space calculation Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow. When we send data, if an skb exists at the tail of the write queue, the kernel will attempt to append the new data to that skb. However, the code that checks for available space in the skb is flawed: '''

  2. Aug 5, 2026 · EUVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: tcp: Correct signedness in skb remaining space calculation Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow. When we send data, if an skb exists at the tail of the write queue, the kernel will attempt to append the new data to that skb. However, the code that checks for available space in the skb is flawed: '''

Sources

  • CVE.orgVulnerability recordCVE-2025-38463

    Official CVE identifier

    cve.org
  • EUVDVulnerability recordEUVD-2025-22678

    In the Linux kernel, the following vulnerability has been resolved: tcp: Correct signedness in skb remaining space calculation Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow. When we send data, if an skb exists at the tail of the write queue, the kernel will

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Aug 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.