Linux: Out-of-bounds Write
CVE-2026-53002 is a critical-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 9.8 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 2f793ba78470a99f40389b7dc60a81d9f5ad3956, 6bbf829b4c1b44c941c47dd0d710f1393258f3d5, ab64e61c9323fa6de21bd20da1ddb29a0fb65d34 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 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to 2f793ba78470a99f40389b7dc60a81d9f5ad3956 or 6bbf829b4c1b44c941c47dd0d710f1393258f3d5 or ab64e61c9323fa6de21bd20da1ddb29a0fb65d34 or 1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.141, 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 | 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, 2f793ba78470a99f40389b7dc60a81d9f5ad3956; 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, 6bbf829b4c1b44c941c47dd0d710f1393258f3d5; 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, ab64e61c9323fa6de21bd20da1ddb29a0fb65d34; 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, 1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e; 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, a8e0a32a23d3f34862af3b4da792ecb3a891a9a3; 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, 8e3be0d12615a173fe260cd42753ca7a001acbf2; 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, c08ff52e44945e6ef4ce0790f49ea761b060c45b; 9fafcd7b203229c3f3893a475741afc27e276306 up to, but not including, 6e7066bdb481a87fe88c4fa563e348c03b2d373d; and 1 more ranges | 2f793ba78470a99f40389b7dc60a81d9f5ad3956, 6bbf829b4c1b44c941c47dd0d710f1393258f3d5, ab64e61c9323fa6de21bd20da1ddb29a0fb65d34, 1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e, a8e0a32a23d3f34862af3b4da792ecb3a891a9a3, 8e3be0d12615a173fe260cd42753ca7a001acbf2 |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| 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 | 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, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.91; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.10 | 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33 |
| Red Hat | Enterprise Linux | 7.0; 8.0; 9.0; 10.0 | Not stated |
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
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA |
| CVSS 3.1 | 7.0 | High | CNA |
Official description
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: remove sprintf usage Replace it with scnprintf, the buffer sizes are expected to be large enough to hold the result, no need for snprintf+overflow check. Increase buffer size in mangle_content_len() while at it. BUG: KASAN: stack-out-of-bounds in vsnprintf+0xea5/0x1270 Write of size 1 at addr [..] vsnprintf+0xea5/0x1270 sprintf+0xb1/0xe0 mangle_content_len+0x1ac/0x280 nf_nat_sdp_session+0x1cc/0x240 process_sdp+0x8f8/0xb80 process_invite_request+0x108/0x2b0 process_sip_msg+0x5da/0xf50 sip_help_tcp+0x45e/0x780 nf_confirm+0x34d/0x990 [..]
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e
- git.kernel.org/stable/c/2f793ba78470a99f40389b7dc60a81d9f5ad3956
- git.kernel.org/stable/c/6bbf829b4c1b44c941c47dd0d710f1393258f3d5
- git.kernel.org/stable/c/6e7066bdb481a87fe88c4fa563e348c03b2d373d
- git.kernel.org/stable/c/8e3be0d12615a173fe260cd42753ca7a001acbf2
- git.kernel.org/stable/c/a8e0a32a23d3f34862af3b4da792ecb3a891a9a3
- git.kernel.org/stable/c/ab64e61c9323fa6de21bd20da1ddb29a0fb65d34
- git.kernel.org/stable/c/c08ff52e44945e6ef4ce0790f49ea761b060c45b
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2026-53002Third Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2492329Third Party Advisory
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53002.jsonThird Party Advisory
Other references
Recent Out-of-bounds Write vulnerabilities
- 7.8 High severity
- 9.1 Critical severity
- 7.1 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.