CVE-2025-37749Network attack vector

Remote kernel crash via short PPP frames

Published May 1, 2025 · Updated Aug 5, 2026

Out-of-bounds read in affected Linux kernel branches allows remote attackers to crash hosts via short PPP frames. ppp_sync_txmung reads data[0] through data[2] without first ensuring that the skb linear buffer contains three bytes. An unauthenticated peer with an established PPPoE, PPTP, or L2TP session can trigger a kernel oops or panic and an indirect oracle over adjacent kernel heap bytes.

CVSS severity8.2
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in affected Linux kernel branches allows remote attackers to crash hosts via short PPP frames. ppp_sync_txmung reads data[0] through data[2] without first ensuring that the skb linear buffer contains three bytes. An unauthenticated peer with an established PPPoE, PPTP, or L2TP session can trigger a kernel oops or panic and an indirect oracle over adjacent kernel heap bytes.

The record

CVE
CVE-2025-37749
Published
May 1, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1f6eb9fa87a781d5370c0de7794ae242f1a95ee5
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <529401c8f12ecc35f9ea5d946d5a5596cf172b48
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e8a6bf43cea4347121ab21bb1ed8d7bef7e732e
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <99aa698dec342a07125d733e39aab4394b3b7e05
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aabc6596ffb377c4c9c8f335124b92ea282c9821
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b4c836d33ca888695b2f2665f948bc1b34fbd533
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <de5a4f0cba58625e88b7bebd88f780c8c0150997
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fbaffe8bccf148ece8ad67eb5d7aa852cabf59c8
  10. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1f6eb9fa87a781d5370c0de7794ae242f1a95ee5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <529401c8f12ecc35f9ea5d946d5a5596cf172b48; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e8a6bf43cea4347121ab21bb1ed8d7bef7e732e; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <99aa698dec342a07125d733e39aab4394b3b7e05; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aabc6596ffb377c4c9c8f335124b92ea282c9821; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b4c836d33ca888695b2f2665f948bc1b34fbd533; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <de5a4f0cba58625e88b7bebd88f780c8c0150997; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fbaffe8bccf148ece8ad67eb5d7aa852cabf59c8; version=2.6.12

Published CVSS scores

8.2LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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