NVD / CVE Program· CNA GitHub_M

CVE-2026-34978: OpenPrinting CUPS: Path traversal in RSS notify-recipient-uri enables file write outside CacheDir/rss (and clobbering of job.cache)

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: 0.42% (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: azl3 cups 2.4.16-1 on Azure Linux 3.0 2.4.17-1.

Low priority for now. Upgrade to azl3 cups 2.4.16-1 on Azure Linux 3.0 2.4.17-1 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

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, the RSS notifier allows .. path traversal in notify-recipient-uri (e.g., rss:///../job.cache), letting a remote IPP client write RSS XML bytes outside CacheDir/rss (anywhere that is lp-writable). In particular, because CacheDir is group-writable by default (typically root:lp and mode 0770), the notifier (running as lp) can replace root-managed state files via temp-file + rename(). This PoC clobbers CacheDir/job.cache with RSS XML, and after restarting cupsd the scheduler fails to parse the job cache and previously queued jobs disappear. At time of publication, there are no publicly available patches.

MediumCVSS 6.5 · v3.1—No exploit Fix available

Published: Apr 3, 2026
Updated: Jul 20, 2026
EPSS: 0.4% · 36th percentile
CWE: CWE-22

Report tools

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Action score

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: yes
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.

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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?

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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.

Vendor	Product	CPE
openprinting	cups	cpe:2.3:a:openprinting:cups

Affected versions

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

openprinting cupsup to 2.4.16 inclusive

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.

OpenPrinting cups
- <= 2.4.16affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Alpine:v3.20	cups	before 2.4.18-r0	2.4.18-r0
Debian:12	cups	from 0	—
Debian:14	cups	before 2.4.17-1	2.4.17-1
openSUSE:Tumbleweed	cups	before 2.4.17-1.1	2.4.17-1.1
Red Hat:hummingbird:1	cups	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
Red Hat:hummingbird:1	cups-client	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
Red Hat:hummingbird:1	cups-devel	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
Red Hat:hummingbird:1	cups-filesystem	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
Red Hat:hummingbird:1	cups-ipptool	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
Red Hat:hummingbird:1	cups-libs	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
Red Hat:hummingbird:1	cups-lpd	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
Red Hat:hummingbird:1	cups-printerapp	before 0:2.4.17-1.hum1	0:2.4.17-1.hum1
SUSE:Linux Enterprise Micro 5.3	cups	before 2.2.7-150000.3.93.1	2.2.7-150000.3.93.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5	cups	before 1.7.5-20.67.1	1.7.5-20.67.1

Same product

openprinting: all records

Other highest-scoring records for the same primary product.

CVE-2025-58060cups has Authentication bypass with AuthType Negotiate
32Monitor
CVE-2023-4504OpenPrinting CUPS/libppd Postscript Parsing Heap Overflow
28Monitor
CVE-2023-34241CUPS vulnerable to use-after-free in cupsdAcceptClient()
28Monitor

Published before and after this one in the same product

← EarlierCVE-2025-61915Nov 29, 2025 · OpenPrinting CUPS vulnerable to stack based out-of-bound write
26Monitor
← EarlierCVE-2026-27447Apr 3, 2026 · OpenPrinting CUPS: Authorization bypass via case-insensitive group-member lookup
25Monitor
Later →CVE-2026-34979Apr 3, 2026 · OpenPrinting CUPS: Heap overflow in `get_options()`
21Monitor

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
azl3 cups 2.4.16-1 on Azure Linux 3.0	2.4.17-1 · CBL-Mariner Releases	Microsoft (MSRC)
alpine:cups	2.4.18-r0 · Alpine:v3.20	Package registry (OSV)
debian:cups	2.4.17-1 · Debian:14	Package registry (OSV)
opensuse:cups	2.4.17-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
red hat:cups	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:cups-client	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:cups-devel	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:cups-filesystem	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:cups-ipptool	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:cups-libs	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:cups-lpd	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:cups-printerapp	0:2.4.17-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
suse:cups	1.7.5-20.67.1 · SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5	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.

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.

No commit or PR link among the references.

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-2026-61702195 days apartOpenPrinting CUPS: root-side banner file disclosure
21Monitor

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: none
Integrity: low · data or configuration can be modified
Availability: low · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: Low
Availability impact: Low

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

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

nvd-secondary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

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

Vulnerable

1const file = path.join(ROOT, req.query.name);
2res.sendFile(file);

Fixed

1const file = path.resolve(ROOT, req.query.name);
2if (!file.startsWith(ROOT + path.sep)) {
3  return res.sendStatus(400);
4}
5res.sendFile(file);

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

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

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