CVE-2026-49853VulnerabilityPublished 14 Jul 2026

snakeviz · python311-tornado6-6.5.7-1.1 on GA media

Affects snakevizSource GCVE Database

Not known to be exploited : upgrade to 2.2.2_4 when convenient.

Data as of 26 Oct 2026, 09:16 UTC

Severity

Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.2.2_4, 2.7.1_2

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade snakeviz to 2.2.2_4; livereload to 2.7.1_2.

Affected software

Product	Affected	Fixed in
Homebrewsnakeviz`pkg:brew/snakeviz`Other threats	Affected >=2.2.0 <2.2.2_4	Fixed in 2.2.2_4
Homebrewlivereload`pkg:brew/livereload`Other threats	Affected >=2.7.1 <2.7.1_2	Fixed in 2.7.1_2
Ubuntu:Pro:16.04:LTSpython-tornado`pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-infra-legacy/xenial`Other threats	Affected =4.2.1-1ubuntu2 =4.2.1-1ubuntu3 =4.2.1-1ubuntu3.1 =4.2.1-1ubuntu3.1+esm1 =4.2.1-1ubuntu3.1+esm2 =4.2.1-1ubuntu3.1+esm3 =4.2.1-1ubuntu3.1+esm4	Fixed in–
Ubuntu:Pro:18.04:LTSpython-tornado`pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/bionic`Other threats	Affected =4.5.1-2.1~build2 =4.5.2-1 =4.5.3-1 =4.5.3-1ubuntu0.1 =4.5.3-1ubuntu0.2 =4.5.3-1ubuntu0.2+esm1 =4.5.3-1ubuntu0.2+esm2 =4.5.3-1ubuntu0.2+esm3 =4.5.3-1ubuntu0.2+esm4	Fixed in–
Ubuntu:Pro:20.04:LTSpython-tornado`pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/focal`Other threats	Affected =5.1.1-4ubuntu1 =5.1.1-4ubuntu5 =6.0.3+really5.1.1-2 =6.0.3+really5.1.1-2build1 =6.0.3+really5.1.1-2build2 =6.0.3+really5.1.1-3 =6.0.3+really5.1.1-3ubuntu0.1~esm1 =6.0.3+really5.1.1-3ubuntu0.1~esm3 =6.0.3+really5.1.1-3ubuntu0.1~esm5 =6.0.3+really5.1.1-3ubuntu0.1~esm7	Fixed in–
Ubuntu:Pro:22.04:LTSpython-tornado`pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps/jammy`Other threats	Affected =6.1.0-1build1 =6.1.0-2 =6.1.0-3 =6.1.0-3build1 =6.1.0-3ubuntu0.1~esm1 =6.1.0-3ubuntu0.1~esm2 =6.1.0-3ubuntu0.1~esm4 =6.1.0-3ubuntu0.1~esm5 =6.1.0-3ubuntu0.1~esm6	Fixed in–
Ubuntu:24.04:LTSpython-tornado`pkg:deb/ubuntu/python-tornado?arch=source&distro=noble`Other threats	Affected =6.3.2-1 =6.4.0-0ubuntu1 =6.4.0-1 =6.4.0-1build1 =6.4.0-1ubuntu0.1 =6.4.0-1ubuntu0.2 =6.4.0-1ubuntu0.4 =6.4.0-1ubuntu0.5 =6.4.0-1ubuntu0.6	Fixed in–
Ubuntu:26.10python-tornado`pkg:deb/ubuntu/python-tornado?arch=source&distro=stonking`Other threats	Affected =6.5.4-0.1 =6.5.5-2 =6.5.5-4 =6.5.5-5 =6.5.5-5ubuntu1.1	Fixed in–
Ubuntu:26.04:LTSpython-tornado`pkg:deb/ubuntu/python-tornado?arch=source&distro=resolute`Other threats	Affected =6.4.2-3 =6.5.2-3 =6.5.4-0.1 =6.5.4-0.1ubuntu0.1 =6.5.4-0.1ubuntu0.2	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Tornado to version 6.5.6 or later, where this vulnerability is fixed by properly removing sensitive headers on redirects that change scheme, host, or port. No other mitigation is indicated or required.

Description

## Summary When SimpleAsyncHTTPClient follows a 3xx redirect, it shallow-copies the original HTTPRequest, rewrites the URL, decrements max_redirects, and removes only the Host header. It does not clear Authorization, auth_username, auth_password, or auth_mode when the redirect target changes origin. As a result, credentials intended for one origin can be forwarded to a different origin when follow_redirects=True, which is the default. Beginning in Tornado 6.5.6, `SimpleAsyncHTTPClient` matches the default behavior of `libcurl` (and therefore `CurlAsyncHTTPClient`): When a redirect changes the scheme, host, or port of the url, the `Authorization` and `Cookie` headers will be removed when following the redirect.

Impact

Sensitive authentication information such as Authorization headers and authentication credentials could be exposed to unintended hosts during HTTP redirects, potentially allowing unauthorized actors to access protected resources or credentials. The CVSS score of 7.7 (high severity) reflects the network attack vector, low attack complexity, and high confidentiality impact without integrity or availability impact.

Summary

CVE-2026-49853 describes an information exposure vulnerability in Tornado's SimpleAsyncHTTPClient before version 6.5.6. When following HTTP redirects, the client shallow-copied the original request but only removed the Host header, leaving sensitive authentication headers intact even if the redirect changed the scheme, host, or port. This could lead to unauthorized disclosure of sensitive credentials or tokens. The vulnerability is addressed by properly clearing these headers in version 6.5.6.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-201Insertion of Sensitive Information Into Sent Data (opens in a new tab)
Base weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.
Requirements
Specify which data in the software should be regarded as sensitive. Consider which types of users should have access to which types of data.
Implementation
Ensure that any possibly sensitive data specified in the requirements is verified with designers to ensure that it is either a calculated risk or mitigated elsewhere.
System Configuration
Setup default error messages so that unexpected errors do not disclose sensitive information.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Choosing Message Identifier (opens in a new tab)
Exploiting Incorrectly Configured SSL/TLS (opens in a new tab)
WiFi MAC Address Tracking (opens in a new tab)
WiFi SSID Tracking (opens in a new tab)
Cellular Broadcast Message Request (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Exponential Data Expansion (opens in a new tab)
Serialized Data Parameter Blowup (opens in a new tab)
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-1050Excessive Platform Resource Consumption within a Loop (opens in a new tab)
Base weakness
The product has a loop body or loop condition that contains a control element that directly or indirectly consumes platform resources, e.g. messaging, sessions, locks, or file descriptors.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 22 Jul 2026, 20:59 UTC

WeaknessesCWE-200, CWE-201, CWE-770 +1

Technical details

References

Community reviews

Related threats