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

CVE-2026-55862: pupnp: Incomplete fix for CVE-2021-28302: recursive DOM functions cause stack overflow

Noroxi assessment

Priority: Monitor (action score 26/100)

  • 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: 0.46% (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: pupnp pupnp 2.0.0.

Low priority for now. Upgrade to pupnp pupnp 2.0.0 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

pupnp is an SDK for development of UPnP device and control point applications. Prior to 2.0.0, multiple ixml DOM traversal functions process deeply nested XML with unbounded recursion. The iterative XML parser accepts the document, but ixmlPrintDomTreeRecursive in ixml/src/ixml.c and ixmlNode_getElementsByTagNameRecursive, ixmlNode_getElementsByTagNameNSRecursive, ixmlNode_cloneNodeTreeRecursive, and ixmlNode_isAncestor in ixml/src/node.c recurse over firstChild and nextSibling links. An unauthenticated peer on the local network can supply deeply nested XML through a SOAP request, exhaust a service thread's stack, and crash the UPnP service. This is an incomplete-fix case for CVE-2021-28302 because its remediation converted ixmlNode_free but left these traversal paths recursive. This issue is fixed in 2.0.0.

MediumCVSS 6.5 · v3.1—No exploit Fix available
Published
Oct 16, 2026
Updated
Oct 23, 2026
EPSS
0.4% · 39th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
6.5
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

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

Follow CVE-2026-55862

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
pupnp projectpupnp

Affected versions

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

  • pupnp project pupnpbefore 2.0.0

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.

  • pupnp pupnp

    • < 2.0.0affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:13pupnpfrom 0—
Debian:14pupnpbefore 1:22.1.8-21:22.1.8-2

Other highest-scoring records for the same primary product.

  • CVE-2021-29462DNS rebinding in pupnp
    39Monitor
  • CVE-2026-77630pupnp: Denial of service via blocking DNS resolution in parse_uri()/GENA callback parsing
    30Monitor
  • CVE-2026-57487libupnp chunked HTTP bodies can bypass g_maxContentLength and be fully buffered
    30Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2021-28302Mar 12, 2021 · A stack overflow in pupnp before version 1.14.5 can cause the denial of service through the Parser_parseDocument() function.
    30Monitor
  • Later →CVE-2026-57486Oct 16, 2026 · pupnp: NULL pointer dereference in ixmlNode_compare crashes on non-namespaced attributes
    30Monitor
  • Later →CVE-2026-57488Oct 16, 2026 · pupnp: Integer truncation in HTTP Content-Length parsing enables request smuggling
    28Monitor

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
pupnp pupnp2.0.0 · descriptionVendor (CNA)
debian:pupnp1:22.1.8-2 · Debian:14Package 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. TodayOct 26, 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.

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

CVSS vector

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

Change log

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

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

References

Show all references (1 more)

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

All records