Linux: Out-of-bounds Read
CVE-2026-53268 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4cdda7f868f48e2f81579371584fdbdce37df2c8, 8a1d6e40dedfe1068aee094d851bd69e289c9fd6, 0afc802160af0df61ed374fdb97fb34cfe5cdf2f as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.52% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 4cdda7f868f48e2f81579371584fdbdce37df2c8 or 8a1d6e40dedfe1068aee094d851bd69e289c9fd6 or 0afc802160af0df61ed374fdb97fb34cfe5cdf2f or 7c34f91305292083253df6a9f6c8ede02d4ccaea, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, 4cdda7f868f48e2f81579371584fdbdce37df2c8; 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, 8a1d6e40dedfe1068aee094d851bd69e289c9fd6; 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, 0afc802160af0df61ed374fdb97fb34cfe5cdf2f; 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, 7c34f91305292083253df6a9f6c8ede02d4ccaea; 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, ddddd8271359961e403d11c90c9ba9fc38914f7e; 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, 9e5da2379f968a3ea5a6e38921ab6201576466dc; 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, 573810f61bcd6b6815e2ff53bbdd2b9c9d747176; 869f37d8e48f3911eb70f38a994feaa8f8380008 up to, but not including, 66eba0ffce3b7e11449946b4cbbef8ea36112f56; and 1 more ranges | 4cdda7f868f48e2f81579371584fdbdce37df2c8, 8a1d6e40dedfe1068aee094d851bd69e289c9fd6, 0afc802160af0df61ed374fdb97fb34cfe5cdf2f, 7c34f91305292083253df6a9f6c8ede02d4ccaea, ddddd8271359961e403d11c90c9ba9fc38914f7e, 9e5da2379f968a3ea5a6e38921ab6201576466dc |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | all versions | Not stated |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Linux | Linux Kernel | 2.6.20 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; 6.19 up to, but not including, 7.0.13; 7.1 | 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack_irc: fix possible out-of-bounds read When parsing fails after we've matched the command string we should bail out instead of trying to match a different command. This helper should be deprecated, given prevalence of TLS I doubt it has any relevance in 2026.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/0afc802160af0df61ed374fdb97fb34cfe5cdf2f
- git.kernel.org/stable/c/4cdda7f868f48e2f81579371584fdbdce37df2c8
- git.kernel.org/stable/c/573810f61bcd6b6815e2ff53bbdd2b9c9d747176
- git.kernel.org/stable/c/66eba0ffce3b7e11449946b4cbbef8ea36112f56
- git.kernel.org/stable/c/7c34f91305292083253df6a9f6c8ede02d4ccaea
- git.kernel.org/stable/c/8a1d6e40dedfe1068aee094d851bd69e289c9fd6
- git.kernel.org/stable/c/9e5da2379f968a3ea5a6e38921ab6201576466dc
- git.kernel.org/stable/c/ddddd8271359961e403d11c90c9ba9fc38914f7e
Other references
Recent Out-of-bounds Read vulnerabilities
- 7.5 High severity
- 7.1 High severity
- 8.4 High severity
- 9.1 Critical severity
- 8.2 High severity
- 7.1 High severity
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