The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - ipv6: avoid overflows in ip6_datagram_send_ctl() Yiming Qian reported : <quote> I believe I found a     locally triggerable kernel bug in the IPv6 sendmsg ancillary-data path that can panic the kernel via     `skb_under_panic()` (local DoS). The core issue is a mismatch between: - a 16-bit length accumulator     (`struct ipv6_txoptions::opt_flen`, type `__u16`) and - a pointer to the *last* provided destination-     options header (`opt->dst1opt`) when multiple `IPV6_DSTOPTS` control messages (cmsgs) are provided. -     `include/net/ipv6.h`: - `struct ipv6_txoptions::opt_flen` is `__u16` (wrap possible). (lines 291-307,     especially 298) - `net/ipv6/datagram.c:ip6_datagram_send_ctl()`: - Accepts repeated `IPV6_DSTOPTS` and     accumulates into `opt_flen` without rejecting duplicates. (lines 909-933) -     `net/ipv6/ip6_output.c:__ip6_append_data()`: - Uses `opt->opt_flen + opt->opt_nflen` to compute header     sizes/headroom decisions. (lines 1448-1466, especially 1463-1465) -     `net/ipv6/ip6_output.c:__ip6_make_skb()`: - Calls `ipv6_push_frag_opts()` if `opt->opt_flen` is non-zero.
    (lines 1930-1934) - `net/ipv6/exthdrs.c:ipv6_push_frag_opts()` / `ipv6_push_exthdr()`: - Push size comes     from `ipv6_optlen(opt->dst1opt)` (based on the pointed-to header). (lines 1179-1185 and 1206-1211) 1.
    `opt_flen` is a 16-bit accumulator: - `include/net/ipv6.h:298` defines `__u16 opt_flen; /* after fragment     hdr */`. 2. `ip6_datagram_send_ctl()` accepts *repeated* `IPV6_DSTOPTS` cmsgs and increments `opt_flen`     each time: - In `net/ipv6/datagram.c:909-933`, for `IPV6_DSTOPTS`: - It computes `len = ((hdr->hdrlen + 1)     << 3);` - It checks `CAP_NET_RAW` using `ns_capable(net->user_ns, CAP_NET_RAW)`. (line 922) - Then it     does: - `opt->opt_flen += len;` (line 927) - `opt->dst1opt = hdr;` (line 928) There is no duplicate     rejection here (unlike the legacy `IPV6_2292DSTOPTS` path which rejects duplicates at     `net/ipv6/datagram.c:901-904`). If enough large `IPV6_DSTOPTS` cmsgs are provided, `opt_flen` wraps while     `dst1opt` still points to a large (2048-byte) destination-options header. In the attached PoC (`poc.c`): -     32 cmsgs with `hdrlen=255` => `len = (255+1)*8 = 2048` - 1 cmsg with `hdrlen=0` => `len = 8` - Total     increment: `32*2048 + 8 = 65544`, so `(__u16)opt_flen == 8` - The last cmsg is 2048 bytes, so `dst1opt`     points to a 2048-byte header. 3. The transmit path sizes headers using the wrapped `opt_flen`: - In     `net/ipv6/ip6_output.c:1463-1465`: - `headersize = sizeof(struct ipv6hdr) + (opt ? opt->opt_flen +     opt->opt_nflen : 0) + ...;` With wrapped `opt_flen`, `headersize`/headroom decisions underestimate what     will be pushed later. 4. When building the final skb, the actual push length comes from `dst1opt` and is     not limited by wrapped `opt_flen`: - In `net/ipv6/ip6_output.c:1930-1934`: - `if (opt->opt_flen) proto =     ipv6_push_frag_opts(skb, opt, proto);` - In `net/ipv6/exthdrs.c:1206-1211`, `ipv6_push_frag_opts()` pushes     `dst1opt` via `ipv6_push_exthdr()`. - In `net/ipv6/exthdrs.c:1179-1184`, `ipv6_push_exthdr()` does: -     `skb_push(skb, ipv6_optlen(opt));` - `memcpy(h, opt, ipv6_optlen(opt));` With insufficient headroom,     `skb_push()` underflows and triggers `skb_under_panic()` -> `BUG()`: - `net/core/skbuff.c:2669-2675`     (`skb_push()` calls `skb_under_panic()`) - `net/core/skbuff.c:207-214` (`skb_panic()` ends in `BUG()`) -     The `IPV6_DSTOPTS` cmsg path requires `CAP_NET_RAW` in the target netns user namespace     (`ns_capable(net->user_ns, CAP_NET_RAW)`). - Root (or any task with `CAP_NET_RAW`) can trigger this     without user namespaces. - An unprivileged `uid=1000` user can trigger this if unprivileged user     namespaces are enabled and it can create a userns+netns to obtain namespaced `CAP_NET_RAW` (the attached     PoC does this). - Local denial of service: kernel BUG/panic (system crash). - ---truncated---     (CVE-2026-31415)

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Linux Distros Unpatched Vulnerability : CVE-2026-31415

medium Nessus Plugin ID 306176

Version 1.6

Version 1.5

Version 1.4

Version 1.3

Version 1.2

Version 1.1

Version 1.6 May 3, 2026, 4:59 AM Detection (updated detection logic) Plugin metadata Plugin Feed: 202605030459
Version 1.5 May 2, 2026, 11:12 PM Detection (updated detection logic) Plugin metadata Plugin Feed: 202605022312
Version 1.4 Apr 25, 2026, 4:14 PM Detection (updated detection logic) Plugin metadata Plugin Feed: 202604251614
Version 1.3 Apr 17, 2026, 5:33 AM Detection (updated detection logic) Plugin metadata Plugin Feed: 202604170533
Version 1.2 Apr 14, 2026, 10:48 PM CVSS metrics ("CVSSv2 score" set to 4.9) CVSS metrics ("CVSSv2 vector" set to "CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C") CVSS metrics ("CVSSv3 score" set to 5.5) CVSS metrics ("CVSSv3 vector" set to "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H") CVSS temporal metrics ("CVSSv2 temporal vector" set to "CVSS2#E:U/RL:U/RC:C") CVSS temporal metrics ("CVSSv3 temporal vector" set to "CVSS:3.0/E:U/RL:U/RC:C") CVSSv2 score source (set to "CVE-2026-31415") CVSSv2 severity (based on CVE-2026-31415, severity decreased from "High" to "Medium") CVSSv3 severity (based on None, severity decreased from "High" to "Medium") Detection (updated detection logic) Plugin metadata Plugin Feed: 202604142248
Version 1.1 Apr 13, 2026, 9:27 PM New Plugin Feed: 202604132127