CVE-2026-45843

Description

In the Linux kernel, the following vulnerability has been resolved: slip: bound decode() reads against the compressed packet length slhc_uncompress() parses a VJ-compressed TCP header by advancing a pointer through the packet via decode() and pull16(). Neither helper bounds-checks against isize, and decode() masks its return with & 0xffff so it can never return the -1 that callers test for -- those error paths are dead code. A short compressed frame whose change byte requests optional fields lets decode() read past the end of the packet. The over-read bytes are folded into the cached cstate and reflected into subsequent reconstructed packets. Make decode() and pull16() take the packet end pointer and return -1 when exhausted. Add a bounds check before the TCP-checksum read. The existing == -1 tests now do what they were always meant to.

CVSS v3.1 Score

8.2

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

EPSS — Exploit Prediction

0.0028

Probability of exploitation

0.19%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/0511ecb00e61bf28e2fec4bb41fcce385c3a3b2d https://git.kernel.org/stable/c/335957df4ed60f02a2ec0432fbedbf0cc7241d8b https://git.kernel.org/stable/c/37537e42e6df387398bee85cb85070cc80bb1e10 https://git.kernel.org/stable/c/4c1367a2d7aad643a6f87c6931b13cc1a25e8ca7 https://git.kernel.org/stable/c/4cefe32639933d652614b0bd50f818f9af4af78f https://git.kernel.org/stable/c/6268f01ae989013671b526c883e92655342c6f6f https://git.kernel.org/stable/c/9aafba2f49e1fcccc2018816f5836a609c925879 https://git.kernel.org/stable/c/d42bec6e4f6d6d658be365539400b3314b76b2a7

Frequently Asked Questions

What is CVE-2026-45843? +

In the Linux kernel, the following vulnerability has been resolved: slip: bound decode() reads against the compressed packet length slhc_uncompress() parses a VJ-compressed TCP header by advancing a pointer through the packet via decode() and pull16(). Neither helper bounds-checks against isize, and decode() masks its return with & 0xffff so it can never return the -1 that callers test for -- those error paths are dead code. A short compressed frame whose change byte requests optional fields lets decode() read past the end of the packet. The over-read bytes are folded into the cached cstate and reflected into subsequent reconstructed packets. Make decode() and pull16() take the packet end pointer and return -1 when exhausted. Add a bounds check before the TCP-checksum read. The existing == -1 tests now do what they were always meant to. It has a CVSS v3.1 base score of 8.2 (HIGH).

How severe is CVE-2026-45843? +

CVE-2026-45843 has a CVSS v3.1 score of 8.2 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0028, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-45843? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.