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

CVE-2026-116591: compress zstd: Panic on two-block frames

Noroxi assessment

Priority: Monitor (action score 34/100)

  • 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: 0.33% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: klauspost compress 1.20.2; azl3 azurelinux-image-tools 1.6.0-3 on Azure Linux 3.0 Release Notes; azl3 azurelinux-image-tools 1.7.0-2 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to klauspost compress 1.20.2; azl3 azurelinux-image-tools 1.6.0-3 on Azure Linux 3.0 Release Notes; azl3 azurelinux-image-tools 1.7.0-2 on Azure Linux 3.0 Release Notes 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

compress provides various compression algorithms. Prior to 1.20.2, the zstd DecodeAll and streaming decoder paths can panic when a crafted two-block frame reaches huff0.ReadTable with an FSE normalized count of 32768 that readNCount stores in int16 as -32768. The wrapped count allows buildDtable to retain stale fse.Scratch decode-table state from the prior block, and nextFast then derives an out-of-range state and indexes beyond the table instead of returning a decode error. Both blocks are required to preserve and then reuse the stale state, allowing untrusted zstd input to crash an application. This issue is fixed in version 1.20.2.

HighCVSS 8.7 · v4.0—No exploit Fix available
Published
Oct 26, 2026
Updated
Oct 27, 2026
EPSS
0.3% · 26th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.7
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-116591

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.

—

Versions reported by the vendor

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

  • klauspost compress

    • < 1.20.2affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Alpine:v3.24dockerbefore 29.9.3-r029.9.3-r0
Debian:12golang-github-klauspost-compressfrom 0—
Debian:14golang-github-klauspost-compressbefore 1.20.3+ds1-11.20.3+ds1-1
Gogithub.com/klauspost/compressbefore 1.20.21.20.2
Gogithub.com/klauspost/compress/zstdbefore 1.20.21.20.2
openSUSE:Leap 16.0cadvisorbefore 0.60.6-bp160.4.10.60.6-bp160.4.1
openSUSE:Leap 16.0go-containerregistrybefore 0.22.1-bp160.1.10.22.1-bp160.1.1
openSUSE:Leap 16.0haulerbefore 2.1.2-bp160.2.12.1.2-bp160.2.1
openSUSE:Tumbleweedaliyun-clibefore 3.5.2-2.13.5.2-2.1
openSUSE:Tumbleweedamazon-cloudwatch-agentbefore 1.300073.2-3.11.300073.2-3.1
openSUSE:Tumbleweedcadvisorbefore 0.60.6-5.10.60.6-5.1
openSUSE:Tumbleweeddistributionbefore 3.1.2-4.13.1.2-4.1
openSUSE:Tumbleweedgo-containerregistrybefore 0.22.1-3.10.22.1-3.1
openSUSE:Tumbleweedhaulerbefore 2.1.2-3.12.1.2-3.1
openSUSE:Tumbleweedhelmbefore 4.3.1-3.14.3.1-3.1
openSUSE:Tumbleweedhelm3before 3.22.1-2.13.22.1-2.1

Same product

klauspost: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-63209Integer Overflow or Wraparound and Out-of-bounds Write in compress
    30Monitor

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
klauspost compress1.20.2 · descriptionVendor (CNA)
azl3 azurelinux-image-tools 1.6.0-3 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 azurelinux-image-tools 1.7.0-2 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 cert-manager 1.12.15-14 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 cert-manager 1.12.15-15 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 containerd2 2.3.4-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 containerd2 2.3.7-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 containerized-data-importer 1.62.0-8 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 containerized-data-importer 1.62.0-9 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 coredns 1.11.4-21 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 coredns 1.11.4-22 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 docker-buildx 0.14.0-17 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 docker-buildx 0.14.0-19 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 docker-cli 25.0.7-5 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 docker-cli 25.0.7-6 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 docker-compose 2.27.0-14 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 docker-compose 2.27.0-16 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 gh 2.101.0-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 gh 2.102.0-2 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 influxdb 2.7.5-21 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 influxdb 2.7.5-22 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kata-containers 4.1.0.kata0-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kata-containers 4.1.0.kata1-2 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kata-containers-cc 3.15.0.aks0-21 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kata-containers-cc 3.15.0.aks0-23 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 keda 2.14.1-19 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kubernetes 1.30.10-31 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kubernetes 1.30.10-32 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 moby-containerd-cc 1.7.7-17 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 moby-containerd-cc 1.7.7-19 on Azure Linux 3.0Release NotesMicrosoft (MSRC)

+23

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 6, 2026+10 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.

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.

  • CVE-2026-6320927 days apartInteger Overflow or Wraparound and Out-of-bounds Write in compress
    30Monitor

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

  • Anyone who can reach it over the internet 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
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Exploit maturity— → none
  3. Fix✗ → ✓

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

References

Show all references (2 more)

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

All records