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NVD / CVE Program· CNA Linux

CVE-2026-63797: rpmsg: char: Fix use-after-free on probe error path

HighCVSS 8.4 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 33/100)

  • 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: 0.14% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 104d100212396801f1d9d388282f746e23e2bfd6, 1306fc4f76f765727a6d5aefbf08ef0c8f32996f, 1ff3f528e67d20e2b1483dcaba899dc7832b2e6b.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 104d100212396801f1d9d388282f746e23e2bfd6, 1306fc4f76f765727a6d5aefbf08ef0c8f32996f, 1ff3f528e67d20e2b1483dcaba899dc7832b2e6b 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: rpmsg: char: Fix use-after-free on probe error path rpmsg_chrdev_probe() stores the newly allocated eptdev in the default endpoint's priv pointer before calling rpmsg_chrdev_eptdev_add(). If rpmsg_chrdev_eptdev_add() then fails, its error path frees eptdev while the default endpoint may still dispatch callbacks with the stale priv pointer. Avoid publishing eptdev through the default endpoint until rpmsg_chrdev_eptdev_add() succeeds. Messages received before the priv pointer is published should be ignored by rpmsg_ept_cb(). Flow-control updates can hit rpmsg_ept_flow_cb() in the same window, so make both callbacks return success when priv is NULL.

Published
Jul 19, 2026
Updated
Aug 17, 2026
EPSS
0.1% · 3th percentile

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
33 / 40 · 8.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
8.4
CNA · Linux
8.4
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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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Follow CVE-2026-63797

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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

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

    • 5.18affected
    • bc69d10665690492421d926b1cd9a7a36bffd691 and later · before 1306fc4f76f765727a6d5aefbf08ef0c8f32996faffected · git
    • bc69d10665690492421d926b1cd9a7a36bffd691 and later · before ddf13f91ca82c94ef7ad9c41a434a03313f8eb1baffected · git
    • bc69d10665690492421d926b1cd9a7a36bffd691 and later · before c5ebb06c7e24d531b68707168e04698859d642bcaffected · git
    • bc69d10665690492421d926b1cd9a7a36bffd691 and later · before 104d100212396801f1d9d388282f746e23e2bfd6affected · git
    • bc69d10665690492421d926b1cd9a7a36bffd691 and later · before ff268cd9ccbce6472a0658791b417bf11c31ee39affected · git
    • bc69d10665690492421d926b1cd9a7a36bffd691 and later · before 1ff3f528e67d20e2b1483dcaba899dc7832b2e6baffected · git
    • before 5.18not affected · semver
    • 6.1.178 and later · up to and including 6.1.*not affected · semver
    • 6.6.144 and later · up to and including 6.6.*not affected · semver
Affected versions · NVD (5)

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

  • linux linux kernel5.18 and later · before 6.1.178
  • linux linux kernel6.2 and later · before 6.6.144
  • linux linux kernel6.7 and later · before 6.12.95
  • linux linux kernel6.13 and later · before 6.18.38
  • linux linux kernel6.19 and later · before 7.1.3

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:13linuxbefore 6.12.95-16.12.95-1
Debian:14linuxbefore 7.1.3-17.1.3-1

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-2026-53396Jul 19, 2026 · nfsd: fix posix_acl leak and ignored error in nfsd4_create_file
    28Monitor
  • ← EarlierCVE-2026-63793Jul 19, 2026 · ntfs: serialize volume label accesses
    31Monitor
  • Later →CVE-2026-63798Jul 19, 2026 · irqchip/imgpdc: Fix resource leak, add missing chained handler cleanup on remove
    22Monitor

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 Linux104d100212396801f1d9d388282f746e23e2bfd6Vendor (CNA)
Linux Linux1306fc4f76f765727a6d5aefbf08ef0c8f32996fVendor (CNA)
Linux Linux1ff3f528e67d20e2b1483dcaba899dc7832b2e6bVendor (CNA)
Linux Linuxc5ebb06c7e24d531b68707168e04698859d642bcVendor (CNA)
Linux Linuxddf13f91ca82c94ef7ad9c41a434a03313f8eb1bVendor (CNA)
Linux Linuxff268cd9ccbce6472a0658791b417bf11c31ee39Vendor (CNA)
debian:linux6.1.180-1 · Debian:12Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

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.

References

Show all references (5 more)

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

All records