CVE-2023-53566: netfilter: nft_set_rbtree: fix null deref on element insertion
Vulnerability summary
CVE-2023-53566 is a high (CVSS 7.8) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.3% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 8 · Related 6Timeline
- 04-10-2025PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_rbtree: fix null deref on element insertion There is no guarantee that rb_prev() will not return NULL in nft_rbtree_gc_elem(): general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] nft_add_set_elem+0x14b0/0x2990 nf_tables_newsetelem+0x528/0xb30 Furthermore, there is a possible use-after-free while iterating, 'node' can be free'd so we need to cache the next value to use.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.15%
Chance of exploitation in the next 30 days
Percentile
4%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.15% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu108 products
- linux< 5.15.0-83.92
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1044.49
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 7ab87a326f20c52ff4d9972052d085be951c704b, < b76db53ee8802ee5683f8cb401d7e2ec6f9b3d56 | ≥ 181859bdfb9734aca449512fccaee4cacce64aed, < 899aa5638568abf5d69de7a7bb95e4615157375b | ≥ 4aacf3d78424293e318c616016865380b37b9cc5, < 3fa13203b6d90cc3a33af47b058739f92ab82eef | ≥ 2bf1435fa19d2c58054391b3bba40d5510a5758c, < ec5caa765f7f6960011c919c9aeb1467940421f6 | ≥ 318cb24a4c3fce8140afaf84e4d45fcb76fb280b, < a836be60a3aabcedcd9c79f545d409ace1f20ba6 | ≥ c9e6978e2725a7d4b6cd23b2facd3f11422c0643, < a337706c1fb35aac3f26b48aca80421bdbe1d33a | ≥ c9e6978e2725a7d4b6cd23b2facd3f11422c0643, < 61ae320a29b0540c16931816299eb86bf2b66c08 | ≥ 5.10.166, < 5.10.181 | ≥ 5.15.91, < 5.15.113 | ≥ 6.1.9, < 6.1.30 | 6.2
- linux_kernelEOL≥ 5.10.166, < 5.10.181 | ≥ 5.15.91, < 5.15.113 | ≥ 6.1.9, < 6.1.30 | ≥ 6.2.1, < 6.3.4 | 6.2 | 6.2:rc6 | 6.2:rc7 | 6.2:rc8 | 6.4:rc1 | 6.4:rc2
Debian1 product
- linux< 6.1.37-1 | < 6.3.7-1
3 vendors · 111 products
