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

CVE-2026-119204: pypdf: Possible large memory usage when parsing page tree

Noroxi assessment

Priority: Monitor (action score 28/100)

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: 0.30% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No special conditions are required; it is repeatable.
Fixed version: py-pdf pypdf 6.21.4.

Low priority for now. Upgrade to py-pdf pypdf 6.21.4 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

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can consume excessive memory while parsing a crafted PDF page tree containing many shared resources. Page-tree flattening copies page dictionary and inherited resource entries without a document-wide entry budget, allowing the crafted resource structure to cause disproportionate allocations. This issue is fixed in version 6.21.4.

HighCVSS 7.1 · v4.0—No exploit Fix available

Published: Oct 29, 2026
Updated: Oct 29, 2026
EPSS: 0.3% · 23th percentile
CWE: CWE-400

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

CNA vs NVD score

NVD: —
CNA · GitHub_M: 7.1; 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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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.

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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.

py-pdf pypdf
- < 6.21.4affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	pypdf	from 0	—
Debian:12	pypdf2	from 0	—
PyPI	pypdf	before 6.21.4	6.21.4

Same product

py-pdf: all records

Other highest-scoring records for the same primary product.

CVE-2026-119209pypdf: Possible large memory usage when parsing cross-reference streams
28Monitor
CVE-2026-119208pypdf: Possible long runtimes/large memory usage for encrypted PDF files
28Monitor
CVE-2026-119207pypdf: Possible large memory usage for exceptions in strict mode
28Monitor

Published before and after this one in the same product

← EarlierCVE-2026-115585Oct 23, 2026 · pypdf: Possible long runtimes for repeated malformed cross-reference entries (Follow-up)
28Monitor
← EarlierCVE-2026-119203Oct 29, 2026 · pypdf: Possible infinite loop when hitting EOF in standard xref table during trailer search
28Monitor
Later →CVE-2026-119205Oct 29, 2026 · pypdf: Possible infinite loop when cloning dictionaries
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 / package	Fixed version	Source
py-pdf pypdf	6.21.4 · description	Vendor (CNA)
PyPI:pypdf	6.21.4	Package 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.

PublishedOct 29, 2026
Fix recordedOct 29, 2026same day
TodayOct 31, 2026+2 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-2026-1192060 days apartpypdf: Possible long runtimes when retrieving page labels
28Monitor
CVE-2026-1192070 days apartpypdf: Possible large memory usage for exceptions in strict mode
28Monitor
CVE-2026-1192080 days apartpypdf: Possible long runtimes/large memory usage for encrypted PDF files
28Monitor
CVE-2026-1192090 days apartpypdf: Possible large memory usage when parsing cross-reference streams
28Monitor
CVE-2026-1155726 days apartpypdf: Possible long runtimes for repeated references to the same missing object
28Monitor
CVE-2026-1155856 days apartpypdf: Possible long runtimes for repeated malformed cross-reference entries (Follow-up)
28Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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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 special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: P

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

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

cna

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

Exploit maturity— → noneOct 29, 2026, 10:07 PM UTC
Fix✗ → ✓Oct 29, 2026, 10:07 PM UTC

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

References

github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54

Show all references (3 more)

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

All records