In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read pa…
CVE-2026-80603 · published 28 Aug 2026
How serious is it
- Severity: critical, CVSS score 9.1 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-80603?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 2.6.12
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read
parse_dcc() treats data_end as an inclusive end pointer, but its only
caller passes data_limit = ib_ptr + datalen, which points one past the
last valid byte.
The newline search loop iterates while tmp <= data_end, so when no
newline is present, *tmp is read at tmp == data_end, one byte beyond
the region filled by skb_header_pointer().
irc_buffer is kmalloc'd as MAX_SEARCH_SIZE + 1 bytes and datalen is
capped at MAX_SEARCH_SIZE, so the stray read does not fault. The byte
is uninitialized or stale; if it contains an ASCII digit, simple_strtoul
will consume it and produce a wrong DCC IP or port in the conntrack
expectation. The extra allocation byte is also a fragile guard: if the
cap or allocation size changes, this becomes a real out-of-bounds read.
Change the loop and its post-loop check to use strict less-than,
consistent with the caller's exclusive-end convention. Update the
function comment accordingly.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/2393f0bd7a467ad475598f3a5b9de27ca36e3037
- git.kernel.org/stable/c/2b70f61f569bb29acb380e6f616a1bbdee15668f
- git.kernel.org/stable/c/437e0a3854b3a44ec15afa9ab88ec215adf3a2fd
- git.kernel.org/stable/c/910c33e4a8c046c3cc1fa5a465a4d41a1bb398f1
- git.kernel.org/stable/c/abb8c32b88ea3f46beb68c34fe9a3ac8ed664e7e
- git.kernel.org/stable/c/aff589556ed772cb1c0c2d7b4d91ec45c0c39416
- git.kernel.org/stable/c/eeef3b81f449560653662df2dde6f6fe247c5365
- git.kernel.org/stable/c/ef6400ca25a13fd6dedbe8ef4a1d0979bbbfe88a
Merged from NVD. Last updated 24 Oct 2026. All vulnerabilities · RSS · JSON