CVE-2026-93203

Persistent claim CRC corruption via parallel updates

Published Sep 17, 2026 · Updated Sep 18, 2026

Race condition in affected Linux kernel batman-adv releases allows remote attackers on the mesh to corrupt bridge-loop-avoidance claim CRC state. batadv_bla_add_claim() publishes a new claim before adding its CRC, allowing concurrent ownership-change processing to move the backbone pointer before the creation path switches it back without compensating the interim backbone. Reachability requires adjacent mesh access and concurrent processing for the same client; the resulting CRC inconsistency persists because stored claims do not trigger recomputation.

CVSS severity7.1
High
EPSS probability0.33%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in affected Linux kernel batman-adv releases allows remote attackers on the mesh to corrupt bridge-loop-avoidance claim CRC state. batadv_bla_add_claim() publishes a new claim before adding its CRC, allowing concurrent ownership-change processing to move the backbone pointer before the creation path switches it back without compensating the interim backbone. Reachability requires adjacent mesh access and concurrent processing for the same client; the resulting CRC inconsistency persists because stored claims do not trigger recomputation.

The record

CVE
CVE-2026-93203
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <08645ab95768b88e2ff85a89211994651710465b
  2. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <1d390db003cbb52cdd86837608bff3794501a5ea
  3. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <3d4a9ae2c69c0fe4c3c69587288241243bb7a39b
  4. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <8bcfa58c4277bff1882a23547c37ab08aa1de12f
  5. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <a3e07db74f22a85aeeb51c600da5c98b9cbca11f
  6. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <ad982d925f00d860d2467811256ffadcccd9e4a7
  7. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <d5b0e7574da5a485f4dbec32a15911900a4487c2
  8. Affected versionversion=23721387c409087fd3b97e274f34d3ddc0970b74 <e54602d9e38db8573f2097d60c7ea8be0a5af1fa
  9. Affected versionversion=3.5

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=23721387c409087fd3b97e274f34d3ddc0970b74 <08645ab95768b88e2ff85a89211994651710465b; version=23721387c409087fd3b97e274f34d3ddc0970b74 <1d390db003cbb52cdd86837608bff3794501a5ea; version=23721387c409087fd3b97e274f34d3ddc0970b74 <3d4a9ae2c69c0fe4c3c69587288241243bb7a39b; version=23721387c409087fd3b97e274f34d3ddc0970b74 <8bcfa58c4277bff1882a23547c37ab08aa1de12f; version=23721387c409087fd3b97e274f34d3ddc0970b74 <a3e07db74f22a85aeeb51c600da5c98b9cbca11f; version=23721387c409087fd3b97e274f34d3ddc0970b74 <ad982d925f00d860d2467811256ffadcccd9e4a7; version=23721387c409087fd3b97e274f34d3ddc0970b74 <d5b0e7574da5a485f4dbec32a15911900a4487c2; version=23721387c409087fd3b97e274f34d3ddc0970b74 <e54602d9e38db8573f2097d60c7ea8be0a5af1fa; version=3.5

Published CVSS scores

3.1Amazon LinuxCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
7.1GitHub Advisory DatabaseCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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