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NVD / CVE Program· CNA apache

CVE-2026-58187: Apache Traffic Server: Multiplexer plugin chunk decoder enables a denial of service

MediumCVSS 6.3 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 25/100)

  • 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: 0.58% (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.
  • Fixed version: Apache Software Foundation Apache Traffic Server 9.2.15.
  • Severity is disputed: the assigning authority (CNA) scores it 3.7, NVD 6.3.

Low priority for now. Upgrade to Apache Software Foundation Apache Traffic Server 9.2.15 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

The Apache Traffic Server multiplexer plugin overruns its chunk-decode buffer on upstream input, enabling denial of service. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.

Published
Jul 29, 2026
Updated
Oct 1, 2026
EPSS
0.5% · 48th percentile

Report tools

JSON

Action score

25

Monitor

Low priority for now.

CVSS
25 / 40 · 6.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · apache
3.7
NVD has not scored this yet; the score shown is the CNA’s.

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

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-2026-58187

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
apachetraffic server

Versions reported by the vendor

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

  • Apache Software Foundation Apache Traffic Server

    • 8.0.0 and later · up to and including 8.1.11affected · semver
    • 9.0.0 and later · up to and including 9.2.14affected · semver
    • 10.0.0 and later · up to and including 10.1.3affected · semver

Affected versions

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

  • apache traffic server8.0.0 and later · up to 8.1.9 inclusive
  • apache traffic server9.0.0 and later · before 9.2.15
  • apache traffic server10.0.0 and later · before 10.1.4

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12trafficserverfrom 0—

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-31309Apache Traffic Server: HTTP/2 CONTINUATION frames can be utilized for DoS attack
    58Plan
  • CVE-2023-39456Apache Traffic Server: Malformed http/2 frames can cause an abort
    47Plan
  • CVE-2015-3249The HTTP/2 experimental feature in Apache Traffic Server 5.3.x before 5.3.1 allows remote attackers to cause a denial of service…
    41Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-58185Jul 29, 2026 · Apache Traffic Server: Use-after-free in the intercept plugin
    32Monitor
  • ← EarlierCVE-2026-58186Jul 29, 2026 · Apache Traffic Server: webp_transform plugin decodes unsafely and mislabels degraded responses
    32Monitor
  • Later →CVE-2026-58188Jul 29, 2026 · Apache Traffic Server: Memory-safety and limit-bypass errors across experimental plugins
    33Monitor

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
Apache Software Foundation Apache Traffic Server9.2.15 · descriptionVendor (CNA)

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).

Credits

All researchers

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

Variant candidates

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

  • CVE-2026-581540 days apartApache Traffic Server: Memory-safety errors in MIME and header parsing
    36Monitor
  • CVE-2026-581770 days apartApache Traffic Server: Memory-safety and path-traversal errors in the Cripts framework
    33Monitor
  • CVE-2026-581840 days apartApache Traffic Server: header_rewrite plugin cookie handling can corrupt memory
    33Monitor
  • CVE-2026-581880 days apartApache Traffic Server: Memory-safety and limit-bypass errors across experimental plugins
    33Monitor

Not on record for this CVE: patch commit or PR link · public bounty program.

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-787 · Out-of-bounds Write

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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.

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

References

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

All records