How severe is CVE-2023-49277?

CVE-2023-49277 has a CVSS score of 8.3/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-49277?

CVE-2023-49277 affects the following packages: dpaste (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2023-49277?

Update dpaste to 3.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-49277 is resolved across your whole dependency graph.

How do I detect CVE-2023-49277 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dpaste, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-49277 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2023-49277 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-49277 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-49277?

CVE-2023-49277 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 44th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-49277?

CVE-2023-49277 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2023-49277 published, and has it been updated?

CVE-2023-49277 was published on December 1, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

HIGH severity

CVE-2023-49277 — dpaste

HIGHFix: DarrenOfficial/dpaste@44a666a

CVE-2023-49277 is a high-severity (CVSS 8.3) Cross-site Scripting (XSS) vulnerability in dpaste. A fix is available for dpaste — see the affected versions and patch details below.

Reflected Cross-site Scripting Vulnerability in dpaste

Also known asGHSA-r8j9-5cj7-cv39PYSEC-2026-1317

Published

Dec 1, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-49277.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs44th percentile — riskier than 44% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐍dpaste

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

A security vulnerability has been identified in the expires parameter of the dpaste API, allowing for a POST Reflected XSS attack. This vulnerability can be exploited by an attacker to execute arbitrary JavaScript code in the context of a user's browser, potentially leading to unauthorized access, data theft, or other malicious activities.

Patches

A patch has been applied to the dpaste GitHub repository to address the specific content value injection vulnerability.
Users are strongly advised to upgrade to dpaste release v3.8 or later versions, as dpaste versions older than v3.8 are susceptible to the identified security vulnerability.
The patch can be viewed and applied from the following link: dpaste Commit Patch

Workarounds

At this time, the recommended course of action is to apply the provided patch to the affected systems. No known workarounds have been identified, and applying the patch is the most effective way to remediate the vulnerability.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`dpaste`	all versions	3.8`pip install --upgrade 'dpaste==3.8'`

Affected Products

1 product · 1 configurations

Application

dpastedarrennathanael

< 3.8

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dpaste, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update dpaste to 3.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-49277 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact A security vulnerability has been identified in the expires parameter of the dpaste API, allowing for a POST Reflected XSS attack. This vulnerability can be exploited by an attacker to execute arbitrary JavaScript code in the context of a user's browser, potentially leading to unauthorized access, data theft, or other malicious activities. ### Patches - A patch has been applied to the dpaste GitHub repository to address the specific content value injection vulnerability. - Users are strongly advised to upgrade to dpaste release v3.8 or later versions, as dpaste versions older than