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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99056: strparser: make sure __strp_recv isn't running before tearing down the parser

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.16% (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 0984ebc631792acf8fff105112ee74a6b8f1efcc, 61cc5dac60d50dee06cf5c7b7ab246f9c825a715, 933df60a465b1b82ff92dcd6870504da90ba4e9b; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0984ebc631792acf8fff105112ee74a6b8f1efcc, 61cc5dac60d50dee06cf5c7b7ab246f9c825a715, 933df60a465b1b82ff92dcd6870504da90ba4e9b; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1 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: strparser: make sure __strp_recv isn't running before tearing down the parser The comment above strp_done() claims that if strp is stopped, strp_recv will no longer be called. That's only true if the caller has a mechanism (eg locking) to guarantee that strp_recv() calls that started before strp_stop() have completed by the time we call strp_done(). This adds a dummy lock_sock/release_sock pair to guarantee that any in-flight strp_recv() (which runs under either bh_lock_sock or lock_sock, depending if it's called from ->sk_data_ready or strp_work) has completed. Only espintcp can be affected by this race condition, but this patch makes sure no future user of strp can have the bug. This could crash on strp->sk ("general mode" of strp), but this mode has been here for 9 years and has never been used. It'll be gone soon, no point worrying about it. Switch the stopped/paused/etc bits to u8's to avoid races between strp_stop() and strp_pause/unpause(). A reproducer has been published and turns the possible UAF into an exploit [1].

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Oct 23, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 5th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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

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Noroxi analysis

What does it mean in your environment?

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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.

—

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

    • 5.6affected
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before b09071e2f8460b35c7d355addad0fc7b31c6904daffected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 933df60a465b1b82ff92dcd6870504da90ba4e9baffected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 61cc5dac60d50dee06cf5c7b7ab246f9c825a715affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before a18dd388045dc7263d99a07db9de4e0f149ca8f1affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 9f3e9fe1b155e9b4572054d8d140586bc3512ecfaffected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before d2b5f637b9b67a79a50d42614d10653c13b4e449affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before eaa3a29004c063d7e9d5ea55636f693f67e6db0faffected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 0984ebc631792acf8fff105112ee74a6b8f1efccaffected · git
    • before 5.6not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.11-17.2.11-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-99054Oct 23, 2026 · tipc: destroy topsrv workqueues before closing connections
    31Monitor
  • ← EarlierCVE-2026-99055Oct 23, 2026 · tcp: reject net_iov in zerocopy receive mapping hints
    0Monitor
  • Later →CVE-2026-99057Oct 23, 2026 · xen/netfront: don't leak the skb when xennet_fill_frags() fails
    0Monitor

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 Linux0984ebc631792acf8fff105112ee74a6b8f1efccVendor (CNA)
Linux Linux61cc5dac60d50dee06cf5c7b7ab246f9c825a715Vendor (CNA)
Linux Linux933df60a465b1b82ff92dcd6870504da90ba4e9bVendor (CNA)
Linux Linux9f3e9fe1b155e9b4572054d8d140586bc3512ecfVendor (CNA)
Linux Linuxa18dd388045dc7263d99a07db9de4e0f149ca8f1Vendor (CNA)
Linux Linuxb09071e2f8460b35c7d355addad0fc7b31c6904dVendor (CNA)
Linux Linuxd2b5f637b9b67a79a50d42614d10653c13b4e449Vendor (CNA)
Linux Linuxeaa3a29004c063d7e9d5ea55636f693f67e6db0fVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.06.6.161.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.113-1 · Debian:13Package 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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 11, 2026+19 d
EPSS, last 120 days

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

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

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
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
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

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. CVSS— → 7.8
  2. Severity— → high
  3. Exploit maturity— → none
  4. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records