Linux: Use After Free
CVE-2026-53006 is a critical-severity use after free 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 7bff2c8fe5c35ae58bf73104f53db3676e6e5d94, aff0f28f5be803de2452ce702631c021fcd9ce8a, 38bdbc897c0d83a3e2b925a51b69420f1feba29a 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 0.39% 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 7bff2c8fe5c35ae58bf73104f53db3676e6e5d94 or aff0f28f5be803de2452ce702631c021fcd9ce8a or 38bdbc897c0d83a3e2b925a51b69420f1feba29a or 0069813e6ca9309eca78022bcb3aeb1e9ef90a12, 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 | 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, 7bff2c8fe5c35ae58bf73104f53db3676e6e5d94; 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, aff0f28f5be803de2452ce702631c021fcd9ce8a; 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, 38bdbc897c0d83a3e2b925a51b69420f1feba29a; 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, 0069813e6ca9309eca78022bcb3aeb1e9ef90a12; 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, 1e1f0f89ee4692a64be3f3707ff8ac1ae57b03e7; 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, 7c66b368c6ff453f99cb39d84af93e908e51eef2; 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, 085e31a811ef234ef8c3e219c4636dfebfe7e10f; 4b3418fba0fe819197e3359d5ddbef84ba2c59de up to, but not including, f996edd7615e686ada141b7f3395025729ff8ccb; and 1 more ranges | 7bff2c8fe5c35ae58bf73104f53db3676e6e5d94, aff0f28f5be803de2452ce702631c021fcd9ce8a, 38bdbc897c0d83a3e2b925a51b69420f1feba29a, 0069813e6ca9309eca78022bcb3aeb1e9ef90a12, 1e1f0f89ee4692a64be3f3707ff8ac1ae57b03e7, 7c66b368c6ff453f99cb39d84af93e908e51eef2 |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | 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 9.4 Update Services for SAP Solutions | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | 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 | 4.4 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 | 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: ipv6: fix possible UAF in icmpv6_rcv() Caching saddr and daddr before pskb_pull() is problematic since skb->head can change. Remove these temporary variables: - We only access &ipv6_hdr(skb)->saddr and &ipv6_hdr(skb)->daddr when net_dbg_ratelimited() is called in the slow path. - Avoid potential future misuse after pskb_pull() call.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
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/0069813e6ca9309eca78022bcb3aeb1e9ef90a12
- git.kernel.org/stable/c/085e31a811ef234ef8c3e219c4636dfebfe7e10f
- git.kernel.org/stable/c/1e1f0f89ee4692a64be3f3707ff8ac1ae57b03e7
- git.kernel.org/stable/c/38bdbc897c0d83a3e2b925a51b69420f1feba29a
- git.kernel.org/stable/c/7bff2c8fe5c35ae58bf73104f53db3676e6e5d94
- git.kernel.org/stable/c/7c66b368c6ff453f99cb39d84af93e908e51eef2
- git.kernel.org/stable/c/aff0f28f5be803de2452ce702631c021fcd9ce8a
- git.kernel.org/stable/c/f996edd7615e686ada141b7f3395025729ff8ccb
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2026-53006Third Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2492363Third Party Advisory
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53006.jsonThird Party Advisory
Other references
- access.redhat.com/errata/RHSA-2026:45192
- access.redhat.com/errata/RHSA-2026:47010
- access.redhat.com/errata/RHSA-2026:47011
- access.redhat.com/errata/RHSA-2026:47017
- access.redhat.com/errata/RHSA-2026:61932
- access.redhat.com/errata/RHSA-2026:62568
- access.redhat.com/errata/RHSA-2026:64767
- access.redhat.com/errata/RHSA-2026:65710
- access.redhat.com/errata/RHSA-2026:65711
- access.redhat.com/errata/RHSA-2026:65712
- access.redhat.com/errata/RHSA-2026:67721
- access.redhat.com/errata/RHSA-2026:67723
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- cert-portal.siemens.com/productcert/html/ssa-457936.html
Recent Use After Free vulnerabilities
- 7.5 High severity
- 8.8 High severity
- 7.8 High severity
- 8.8 High severity
- 8.8 High severity
- 9.6 Critical severity
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