CVE-2026-98442: vulnerability in Linux
net/sched: act_ct: fix helper UAF due to extensions realloc
Published · Updated
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 94% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_ct: fix helper UAF due to extensions realloc
While calling the helpers, a raw pointer to the extensions area is
wired into expectations list:
-> nf_ct_helper()
-> helper->help()
-> nf_ct_expect_related_report()
-> nf_ct_expect_insert()
-> hlist_add_head_rcu(&exp->lnode, &master_help->expectations)
In case the connection is not confirmed yet, more extensions can be
added afterwards with *_ext_add() calls reallocating the extension
space and leaving the now invalid pointer in the expectations list
that is later accessed while removing the expectation.
Make sure that helpers are called at the end after all the other
extensions are already added.
Note that the helper rejection now leaves the mark and labels set,
but that's not different from how the NAT was handled before or how
the mark and the labels were handled on confirmation failure. And
there are no atomicity guarantees provided by the API anyway.
Affected products
Linux · LinuxRelated CVEs — Linux
In the same product, most dangerous first.
CVE-2024-53197HIGHALSA: usb-audio: Fix potential out-of-bound accesses for Extigy and Mbox devicesEPSS 4.1%KEVCVE-2026-31431HIGHcrypto: algif_aead - Revert to operating out-of-placeEPSS 3.4%KEVCVE-2024-53104HIGHmedia: uvcvideo: Skip parsing frames of type UVC_VS_UNDEFINED in uvc_parse_formatEPSS 3.4%KEVCVE-2025-39682CRITICALtls: fix handling of zero-length records on the rx_listEPSS 2.9%KEVCVE-2024-36971HIGHnet: fix __dst_negative_advice() raceEPSS 2.7%KEVCVE-2025-39964HIGHcrypto: af_alg - Disallow concurrent writes in af_alg_sendmsgEPSS 1.4%KEV
References
https://git.kernel.org/stable/c/1679bbf5fbeac52a310b1a58b2b301bbf388bdbfhttps://git.kernel.org/stable/c/31f5fe29a572037ee19c233dfe506849940c484bhttps://git.kernel.org/stable/c/812c16a255e7773a544e88b39ae6daed25544d30https://git.kernel.org/stable/c/8988f4d11f3fba0ab38122178836c683ad516a05https://git.kernel.org/stable/c/dad19b59da050cb60d3f7023dac2a042a84bf0bd