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NVD / CVE Program· CNA GitHub_M

CVE-2026-27458: LinkAce: Stored XSS in Atom Feed via CDATA Escape in List Description

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: 0.25% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. 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: Kovah LinkAce 2.4.3.

Low priority for now. Upgrade to Kovah LinkAce 2.4.3 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

LinkAce is a self-hosted archive to collect website links. Versions 2.4.2 and below have a Stored Cross-site Scripting vulnerability through the Atom feed endpoint for lists (/lists/feed). An authenticated user can inject a CDATA-breaking payload into a list description that escapes the XML CDATA section, injects a native SVG element into the Atom XML document, and executes arbitrary JavaScript directly in the browser when the feed URL is visited. No RSS reader or additional rendering context is required — the browser's native XML parser processes the injected SVG and fires the onload event handler. This vulnerability exists because the lists feed template outputs list descriptions using Blade's raw syntax ({!! !!}) without sanitization inside a CDATA block. The critical detail is that because the output sits inside <![CDATA[...]]>, an attacker can inject the sequence ]]> to close the CDATA section prematurely, then inject arbitrary XML/SVG elements that the browser parses and executes natively as part of the Atom document. This issue has been fixed in version 2.4.3.

HighCVSS 8.7 · v4.0—No exploit Fix available
Published
Feb 21, 2026
Updated
Jun 17, 2026
EPSS
0.2% · 16th 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 · 0.2%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
total

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:L/UI:N/VC:H/VI:H/VA:L/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-2026-27458

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
linkacelinkace

Affected versions

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

  • linkace linkacebefore 2.4.3

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.

  • Kovah LinkAce

    • < 2.4.3affected

Same product

linkace: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-33953LinkAce's SSRF protection can be bypassed via internal hostname resolution in LinkAce
    34Monitor
  • CVE-2025-62722LinkAce: Stored XSS Vulnerability in Link Title Field Through Social Media Sharing Feature
    34Monitor
  • CVE-2025-53838LinkAce has a Stored One Click XSS vulnerability
    33Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-62720Nov 4, 2025 · LinkAce: Data Exfiltration via Export Functions Allow Access to All Users' Private Links
    28Monitor
  • ← EarlierCVE-2025-62721Nov 4, 2025 · LinkAce: Authorization Bypass Allows Unauthorized Access to All Private Links, Lists, and Tags
    28Monitor
  • Later →CVE-2026-30953Mar 10, 2026 · LinkAce affected by SSRF via link creation: NoPrivateIpRule not applied to LinkStoreRequest
    26Monitor

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
Kovah LinkAce2.4.3 · 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.

No history yet (it accumulates with the daily EPSS job).

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.

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

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

Weakness class (CWE)

CWE-80 · Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

CVSS vector

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

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

All records