UBUNTU-CVE-2026-52999
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix out-of-bounds read on option matching In nf_osf_match(), the nf_osf_hdr_ctx structure is initialized once and passed by reference to nf_osf_match_one() for each fingerprint checked. During TCP option parsing, nf_osf_match_one() advances the shared ctx->optp pointer. If a fingerprint perfectly matches, the function returns early without restoring ctx->optp to its initial state. If the user has configured NF_OSF_LOGLEVEL_ALL, the loop continues to the next fingerprint. However, because ctx->optp was not restored, the next call to nf_osf_match_one() starts parsing from the end of the options buffer. This causes subsequent matches to read garbage data and fail immediately, making it impossible to log more than one match or logging incorrect matches. Instead of using a shared ctx->optp pointer, pass the context as a constant pointer and use a local pointer (optp) for TCP option traversal. This makes nf_osf_match_one() strictly stateless from the caller's perspective, ensuring every fingerprint check starts at the correct option offset.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
4 explicit affected versions
53 explicit affected versions
116 explicit affected versions
87 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
19 explicit affected versions
10 explicit affected versions
6 explicit affected versions
97 explicit affected versions
59 explicit affected versions
24 explicit affected versions
2 explicit affected versions
82 explicit affected versions
83 explicit affected versions
91 explicit affected versions
84 explicit affected versions
76 explicit affected versions
10 explicit affected versions
37 explicit affected versions
26 explicit affected versions
89 explicit affected versions
7 explicit affected versions
84 explicit affected versions
40 explicit affected versions
13 explicit affected versions
44 explicit affected versions
35 explicit affected versions
1 explicit affected versions
49 explicit affected versions
47 explicit affected versions
18 explicit affected versions
40 explicit affected versions
1 explicit affected versions
62 explicit affected versions
45 explicit affected versions
120 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
52 explicit affected versions
124 explicit affected versions
1 explicit affected versions
21 explicit affected versions
7 explicit affected versions
16 explicit affected versions
10 explicit affected versions
20 explicit affected versions
76 explicit affected versions
7 explicit affected versions
48 explicit affected versions
8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
17 explicit affected versions
104 explicit affected versions
12 explicit affected versions
10 explicit affected versions
105 explicit affected versions
12 explicit affected versions
41 explicit affected versions
9 explicit affected versions
9 explicit affected versions
43 explicit affected versions
16 explicit affected versions
6 explicit affected versions
17 explicit affected versions
27 explicit affected versions
34 explicit affected versions
10 explicit affected versions
37 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
39 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
65 explicit affected versions
1 explicit affected versions
26 explicit affected versions
10 explicit affected versions
13 explicit affected versions
34 explicit affected versions
29 explicit affected versions
111 explicit affected versions
13 explicit affected versions
12 explicit affected versions
95 explicit affected versions
41 explicit affected versions
40 explicit affected versions
8 explicit affected versions
100 explicit affected versions
89 explicit affected versions
52 explicit affected versions
33 explicit affected versions
23 explicit affected versions
58 explicit affected versions
10 explicit affected versions
20 explicit affected versions
19 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
10 explicit affected versions
16 explicit affected versions
17 explicit affected versions
5 explicit affected versions
74 explicit affected versions
90 explicit affected versions
10 explicit affected versions
26 explicit affected versions
39 explicit affected versions
1 explicit affected versions
66 explicit affected versions
35 explicit affected versions
48 explicit affected versions
11 explicit affected versions
10 explicit affected versions
13 explicit affected versions
46 explicit affected versions
78 explicit affected versions
16 explicit affected versions
88 explicit affected versions
50 explicit affected versions
10 explicit affected versions
3 explicit affected versions
132 explicit affected versions
1 explicit affected versions
7 explicit affected versions
2 explicit affected versions
15 explicit affected versions
51 explicit affected versions
16 explicit affected versions
18 explicit affected versions
43 explicit affected versions
12 explicit affected versions
70 explicit affected versions
77 explicit affected versions
7 explicit affected versions
27 explicit affected versions
3 explicit affected versions
63 explicit affected versions
121 explicit affected versions
8 explicit affected versions
1 explicit affected versions
43 explicit affected versions
8 explicit affected versions
54 explicit affected versions
3 explicit affected versions
5 explicit affected versions
8 explicit affected versions
6 explicit affected versions
1 explicit affected versions
10 explicit affected versions
7 explicit affected versions
46 explicit affected versions
13 explicit affected versions
110 explicit affected versions
13 explicit affected versions
72 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
36 explicit affected versions
108 explicit affected versions
80 explicit affected versions
56 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
50 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
17 explicit affected versions
11 explicit affected versions
39 explicit affected versions
18 explicit affected versions
14 explicit affected versions
90 explicit affected versions
6 explicit affected versions
7 explicit affected versions
4 explicit affected versions
79 explicit affected versions
10 explicit affected versions
1 explicit affected versions
1 explicit affected versions
1 explicit affected versions
88 explicit affected versions
78 explicit affected versions
78 explicit affected versions
7 explicit affected versions
13 explicit affected versions
43 explicit affected versions
77 explicit affected versions
16 explicit affected versions
119 explicit affected versions
10 explicit affected versions
8 explicit affected versions
45 explicit affected versions
88 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
14 explicit affected versions
11 explicit affected versions
1 explicit affected versions
123 explicit affected versions
19 explicit affected versions
6 explicit affected versions
39 explicit affected versions
77 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix out-of-bounds read on option matching In nf_osf_match(), the nf_osf_hdr_ctx structure is initialized once and passed by reference to nf_osf_match_one() for each fingerprint checked. During TCP option parsing, nf_osf_match_one() advances the shared ctx->optp pointer. If a fingerprint perfectly matches, the function returns early without restoring ctx->optp to its initial state. If the user has configured NF_OSF_LOGLEVEL_ALL, the loop continues to the next fingerprint. However, because ctx->optp was not restored, the next call to nf_osf_match_one() starts parsing from the end of the options buffer. This causes subsequent matches to read garbage data and fail immediately, making it impossible to log more than one match or logging incorrect matches. Instead of using a shared ctx->optp pointer, pass the context as a constant pointer and use a local pointer (optp) for TCP option traversal. This makes nf_osf_match_one() strictly stateless from the caller's perspective, ensuring every fingerprint check starts at the correct option offset.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/f5ca450087c3baf3651055e7a6de92600f827af3
- https://ubuntu.com/security/CVE-2026-52999
- https://ubuntu.com/security/notices/USN-8566-1
- https://ubuntu.com/security/notices/USN-8567-1
- https://ubuntu.com/security/notices/USN-8568-1
- https://ubuntu.com/security/notices/USN-8569-1
- https://ubuntu.com/security/notices/USN-8574-1
- https://ubuntu.com/security/notices/USN-8574-2
- https://ubuntu.com/security/notices/USN-8574-3
- https://ubuntu.com/security/notices/USN-8575-1
- https://ubuntu.com/security/notices/USN-8575-2
- https://ubuntu.com/security/notices/USN-8575-3
- https://ubuntu.com/security/notices/USN-8576-1
- https://ubuntu.com/security/notices/USN-8576-2
- https://ubuntu.com/security/notices/USN-8593-1
- https://ubuntu.com/security/notices/USN-8595-1
- https://ubuntu.com/security/notices/USN-8595-2
- https://ubuntu.com/security/notices/USN-8595-3
- https://ubuntu.com/security/notices/USN-8596-1
- https://ubuntu.com/security/notices/USN-8603-1
- https://ubuntu.com/security/notices/USN-8606-1
- https://ubuntu.com/security/notices/USN-8607-1
- https://ubuntu.com/security/notices/USN-8608-1
- https://ubuntu.com/security/notices/USN-8609-1
- https://ubuntu.com/security/notices/USN-8610-1
- https://ubuntu.com/security/notices/USN-8618-1
- https://ubuntu.com/security/notices/USN-8619-1
- https://ubuntu.com/security/notices/USN-8620-1
- https://ubuntu.com/security/notices/USN-8620-2
- https://ubuntu.com/security/notices/USN-8620-3
- https://ubuntu.com/security/notices/USN-8620-4
- https://www.cve.org/CVERecord?id=CVE-2026-52999