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NVD / CVE Program· CNA Linux

CVE-2026-45842: slip: reject VJ receive packets on instances with no rstate array

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2.6.33, 3.11, 3.13; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1.

Low priority for now. Upgrade to Linux Linux 2.6.33, 3.11, 3.13; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: slip: reject VJ receive packets on instances with no rstate array slhc_init() accepts rslots == 0 as a valid configuration, with the documented meaning of 'no receive compression'. In that case the allocation loop in slhc_init() is skipped, so comp->rstate stays NULL and comp->rslot_limit stays 0 (from the kzalloc of struct slcompress). The receive helpers do not defend against that configuration. slhc_uncompress() dereferences comp->rstate[x] when the VJ header carries an explicit connection ID, and slhc_remember() later assigns cs = &comp->rstate[...] after only comparing the packet's slot number to comp->rslot_limit. Because rslot_limit is 0, slot 0 passes the range check, and the code dereferences a NULL rstate. The configuration is reachable in-tree through PPP. PPPIOCSMAXCID stores its argument in a signed int, and (val >> 16) uses arithmetic shift. Passing 0xffff0000 therefore sign-extends to -1, so val2 + 1 is 0 and ppp_generic.c ends up calling slhc_init(0, 1). Because /dev/ppp open is gated by ns_capable(CAP_NET_ADMIN), the whole path is reachable from an unprivileged user namespace. Once the malformed VJ state is installed, any inbound VJ-compressed or VJ-uncompressed frame that selects slot 0 crashes the kernel in softirq context: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:slhc_uncompress (drivers/net/slip/slhc.c:519) Call Trace: <TASK> ppp_receive_nonmp_frame (drivers/net/ppp/ppp_generic.c:2466) ppp_input (drivers/net/ppp/ppp_generic.c:2359) ppp_async_process (drivers/net/ppp/ppp_async.c:492) tasklet_action_common (kernel/softirq.c:926) handle_softirqs (kernel/softirq.c:623) run_ksoftirqd (kernel/softirq.c:1055) smpboot_thread_fn (kernel/smpboot.c:160) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:164) </TASK> Reject the receive side on such instances instead of touching rstate. slhc_uncompress() falls through to its existing 'bad' label, which bumps sls_i_error and enters the toss state. slhc_remember() mirrors that with an explicit sls_i_error increment followed by slhc_toss(); the sls_i_runt counter is not used here because a missing rstate is an internal configuration state, not a runt packet. The transmit path is unaffected: the only in-tree caller that picks rslots from userspace (ppp_generic.c) still supplies tslots >= 1, and slip.c always calls slhc_init(16, 16), so comp->tstate remains valid and slhc_compress() continues to work.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 27, 2026
Updated
Oct 15, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel2.6.32.70 and later · before 2.6.33
  • linux linux kernel3.2.75 and later · before 3.3
  • linux linux kernel3.4.111 and later · before 3.5
  • linux linux kernel3.10.96 and later · before 3.11
  • linux linux kernel3.12.53 and later · before 3.13
  • linux linux kernel3.14.60 and later · before 3.15
  • linux linux kernel3.18.27 and later · before 3.19
  • linux linux kernel4.1.17 and later · before 4.2
  • linux linux kernel4.3.5 and later · before 5.10.258
  • linux linux kernel5.11 and later · before 5.15.209
  • linux linux kernel5.16 and later · before 6.1.175
  • linux linux kernel6.2 and later · before 6.6.141
  • linux linux kernel6.7 and later · before 6.12.91
  • linux linux kernel6.13 and later · before 6.18.33
  • linux linux kernel6.19 and later · before 7.0.10

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 42fc512469e78939c1e419d3310c47de55bdcbb8, df085f1cb3acd3d75408ff94f366983873bce7d2, a1c3860d3c5fc62bd35f089bcb03f18a37242de9, f82699de104eaf8a7ffc2849a566a94818dd8a3c, 354b254af5c1350de9586af75fe5a821b35bfb33, 5148857f5d4c812cc918cf4627f7880521e987eb, 82185755d90c8047c6f4b589c39998ff3d4ca3ad, a50a93cc99286dc444c7e5ccc7dfb9d58c2d346d, 6b4fa561e26526c62636414d267342c945084f44, 4.4affected
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before 3d71c961febddd855d3ae9a519eeb96c8023f430affected · git
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before 72304fec672e8aac9ee7b9c475db96b37cca8d8daffected · git
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before 4aa9eca6fda2919027dfd7a7cc69334982d89586affected · git
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before c6980e8b1a86288167f34966fa5219031999b6f1affected · git
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before de42f86e2cf5028a97e74c25869d1a962b13c301affected · git
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before 9e1ff0eead073c4f46d874ad2526b7dda5465fafaffected · git
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before 7b0d9e878ec2b21d99ae8051b3dda59cdb66c152affected · git
    • 4ab42d78e37a294ac7bc56901d563c642e03c4ae and later · before e76607442d5b73e1ba6768f501ef815bb58c2c0eaffected · git
    • 2.6.32.70 and later · before 2.6.33affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.10-17.0.10-1
openSUSE:Tumbleweedkernel-sourcebefore 7.0.11-1.17.0.11-1.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-45840May 27, 2026 · openvswitch: cap upcall PID array size and pre-size vport replies
    22Monitor
  • ← EarlierCVE-2026-45841May 27, 2026 · netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULO
    22Monitor
  • Later →CVE-2026-45843May 27, 2026 · slip: bound decode() reads against the compressed packet length
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2.6.33Vendor (CNA)
Linux Linux3.11Vendor (CNA)
Linux Linux3.13Vendor (CNA)
Linux Linux3.15Vendor (CNA)
Linux Linux3.19Vendor (CNA)
Linux Linux3.3Vendor (CNA)
Linux Linux3.5Vendor (CNA)
Linux Linux3d71c961febddd855d3ae9a519eeb96c8023f430Vendor (CNA)
Linux Linux4.2Vendor (CNA)
Linux Linux4.4Vendor (CNA)
Linux Linux4aa9eca6fda2919027dfd7a7cc69334982d89586Vendor (CNA)
Linux Linux72304fec672e8aac9ee7b9c475db96b37cca8d8dVendor (CNA)
Linux Linux7b0d9e878ec2b21d99ae8051b3dda59cdb66c152Vendor (CNA)
Linux Linux9e1ff0eead073c4f46d874ad2526b7dda5465fafVendor (CNA)
Linux Linuxc6980e8b1a86288167f34966fa5219031999b6f1Vendor (CNA)
Linux Linuxde42f86e2cf5028a97e74c25869d1a962b13c301Vendor (CNA)
Linux Linuxe76607442d5b73e1ba6768f501ef815bb58c2c0eVendor (CNA)
azl3 kernel 6.6.139.1-1 on Azure Linux 3.06.6.141.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)
opensuse:kernel-source7.0.11-1.1 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records