Status: UPDATED | Advisory ID: CVE-2026-53239
| CVE | CVE-2026-53239 |
| CVSS Score / Version | 7.8 (High) / CVSS v3.1 |
| Updated | 2026-09-08 |
| CVSS Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CVSS Prose | attack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, and Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP |
| Classified as | CWE-416 (Use After Free) |
| Vendor | Product | Affected Versions | Patch Status |
|---|---|---|---|
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | ||
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | ||
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP |
| Subsystems | General OT |
| Sectors | Multiple |
In the Linux kernel, the following vulnerability has been resolved:
xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()
Fix the race by pruning the bin while still holding xfrm_policy_lock,
before dropping it. Use __xfrm_policy_inexact_prune_bin() directly since
the lock is already held. The wrapper xfrm_policy_inexact_prune_bin()
becomes unused and is removed.
Race:
CPU0 (XFRM_MSG_DELPOLICY) CPU1 (XFRM_MSG_NEWSPDINFO)
========================== ==========================
xfrm_policy_bysel_ctx():
spin_lock_bh(xfrm_policy_lock)
bin = xfrm_policy_inexact_lookup()
__xfrm_policy_unlink(pol)
spin_unlock_bh(xfrm_policy_lock)
xfrm_policy_kill(ret)
// wide window, lock not held
xfrm_hash_rebuild():
spin_lock_bh(xfrm_policy_lock)
__xfrm_policy_inexact_flush():
kfree_rcu(bin) // bin freed
spin_unlock_bh(xfrm_policy_lock)
xfrm_policy_inexact_prune_bin(bin)
// UAF: bin is freed (NVD)
Monitor Siemens's web page for any future patch releases.
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-53239 |
| CVE | https://www.cve.org/CVERecord?id=CVE-2026-53239 |