CVE-2026-80603
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering.
- Exploit odds
- 0.6% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.6% in the next 30 days (EPSS).
- Severity: 9.1 CRITICAL (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.6% · EPSS, next 30 days
- Record status
- Received
Attack profile CVSS 3.1 · 9.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-80603.md and follow it. Check whether this project is affected by CVE-2026-80603. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/2393f0bd7a467ad475598f3a5b9de27ca36e3037
- https://git.kernel.org/stable/c/2b70f61f569bb29acb380e6f616a1bbdee15668f
- https://git.kernel.org/stable/c/437e0a3854b3a44ec15afa9ab88ec215adf3a2fd
- https://git.kernel.org/stable/c/910c33e4a8c046c3cc1fa5a465a4d41a1bb398f1
- https://git.kernel.org/stable/c/abb8c32b88ea3f46beb68c34fe9a3ac8ed664e7e
- https://git.kernel.org/stable/c/aff589556ed772cb1c0c2d7b4d91ec45c0c39416
- https://git.kernel.org/stable/c/eeef3b81f449560653662df2dde6f6fe247c5365
- https://git.kernel.org/stable/c/ef6400ca25a13fd6dedbe8ef4a1d0979bbbfe88a