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NVD / CVE Program· CNA Linux

CVE-2026-64088: batman-adv: tt: fix negative tt_buff_len

Noroxi assessment

Priority: Monitor (action score 35/100)

  • 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: 0.28% (FIRST EPSS).
  • Someone on the same network segment 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 32edd2a28e112064020a2f319a8cb8a9e5a09767, 33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430, 3c96dff00998314983b68a3e7caac07a66ebe496.

Low priority for now. Upgrade to Linux Linux 32edd2a28e112064020a2f319a8cb8a9e5a09767, 33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430, 3c96dff00998314983b68a3e7caac07a66ebe496 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: batman-adv: tt: fix negative tt_buff_len batadv_orig_node::tt_buff_len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_other_tt_response(), tt_buff_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_global_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_other_tt_response().

HighCVSS 8.8 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Aug 11, 2026
EPSS
0.2% · 20th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CNA vs NVD score

NVD
—
CNA · Linux
8.8
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.

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-2026-64088

When you'll hear from us

  • when it enters CISA KEV
  • 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

Affected versions

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

  • linux linux kernel3.1 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 6.6.142
  • linux linux kernel6.7 and later · before 6.12.92
  • linux linux kernel6.13 and later · before 6.18.34
  • linux linux kernel6.19 and later · before 7.0.11
  • linux linux kernel7.1

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

    • 3.1affected
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before 4c4c2f340f4c27373bfcac8dc5032ce7bb474e47affected · git
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before 33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430affected · git
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before 3c96dff00998314983b68a3e7caac07a66ebe496affected · git
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before 32edd2a28e112064020a2f319a8cb8a9e5a09767affected · git
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before 4dab98961426d0cf6a1599cda6950b7596ca2fcdaffected · git
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before 730de8733dd90f70d7580a9b329b971f8e1474a2affected · git
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before ed28ead3420c373a7928622f114bc6168075d1e1affected · git
    • a73105b8d4c765d9ebfb664d0a66802127d8e4c7 and later · before b64963a2ceeb7529310b6cf253a1e540784422f4affected · git
    • before 3.1not affected · 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 7.0.12-17.0.12-1

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-2026-64086Jul 19, 2026 · hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer
    31Monitor
  • ← EarlierCVE-2026-64087Jul 19, 2026 · hwmon: (pmbus/adm1266) reject implausible blackbox record_count
    22Monitor
  • Later →CVE-2026-64089Jul 19, 2026 · batman-adv: tt: fix negative last_changeset_len
    39Monitor

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 Linux32edd2a28e112064020a2f319a8cb8a9e5a09767Vendor (CNA)
Linux Linux33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430Vendor (CNA)
Linux Linux3c96dff00998314983b68a3e7caac07a66ebe496Vendor (CNA)
Linux Linux4c4c2f340f4c27373bfcac8dc5032ce7bb474e47Vendor (CNA)
Linux Linux4dab98961426d0cf6a1599cda6950b7596ca2fcdVendor (CNA)
Linux Linux730de8733dd90f70d7580a9b329b971f8e1474a2Vendor (CNA)
Linux Linuxb64963a2ceeb7529310b6cf253a1e540784422f4Vendor (CNA)
Linux Linuxed28ead3420c373a7928622f114bc6168075d1e1Vendor (CNA)
debian:linux6.1.176-1 · 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).

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 on the same network segment 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
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/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. 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