CVE-2016-9964

MEDIUMEPSS 76th pctl

6.5

CVSS v3

Description

redirect() in bottle.py in bottle 0.12.10 doesn't filter a "\r\n" sequence, which leads to a CRLF attack, as demonstrated by a redirect("233\r\nSet-Cookie: name=salt") call.

CWE-93

How to fix

Remediation Available

python-bottleDebian

Fixed in:0.12.11-1CVE-2016-9964

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Exploit Intelligence

1.76%probability of exploitation in 30 days

76thpercentile

Elevated risk: more likely to be exploited than 76% of all known CVEs.

References

Patch2

Third-Party Advisory2

Related Vulnerabilities

Other CWE-93 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-61884	High	7.5	98%	KEV + Ransom	-
CVE-2022-0666	High	7.5	44%	-	Fix
CVE-2016-3115	Medium	6.4	37%	-	Fix
CVE-2024-20337	High	8.2	30%	-	Fix
CVE-2021-39172	High	8.8	29%	-	Fix
CVE-2016-4975	Medium	6.1	20%	-	Fix

Common questions

How do I fix CVE-2016-9964?

Upgrade python-bottle on debian 11 to 0.12.11-1 or later.

Is CVE-2016-9964 being actively exploited?

Not that we know of. CVE-2016-9964 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.8% is the estimated probability that it will be exploited in the next 30 days. That is higher than 76% of all scored CVEs.

How severe is CVE-2016-9964?

CVE-2016-9964 has a CVSS v3 base score of 6.5, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2016-9964 affect?

Published advisories record a fix for python-bottle (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-06.