CVE-2023-41266
CVE-2023-41266 is a security flaw in Qlik Sense. Attackers can read files on Qlik Sense that should be out of reach from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 7 Dec 2023, and says ransomware gangs have used it.[1]
Qlik Sense is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Qlik has published a fix or advice.
Description
CISA calls it a path traversal in Qlik Sense. In its words: “Qlik Sense contains a path traversal vulnerability that allows a remote, unauthenticated attacker to create an anonymous session by sending maliciously crafted HTTP requests. This anonymous session could allow the attacker to send further requests to unauthorized endpoints.”[1]
The CVE record adds: “A path traversal vulnerability found in Qlik Sense Enterprise for Windows for versions May 2023 Patch 3 and earlier, February 2023 Patch 7 and earlier, November 2022 Patch 10 and earlier, and August 2022 Patch 12 and earlier allows an unauthenticated remote attacker to generate an anonymous session. This allows them to transmit HTTP requests to unauthorized endpoints. This is fixed in August 2023 IR, May 2023 Patch 4, February 2023 Patch 8, November 2022 Patch 11, and August 2022 Patch 13.”[2]
The underlying weakness is improper input validation (CWE-20), in MITRE’s list of common software weaknesses.
It scores 6.5 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Qlik’s advisory has them[3]. CISA names the product as Qlik Sense.
Most families won’t have Qlik Sense; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 7 Dec 2023, 100 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 28 Dec 2023 to fix it.[1] CISA says ransomware gangs have used it.
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 85%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Qlik has published a fix or advice.[3] CISA’s required action: “Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.”[1]
- Check whether you use it.Qlik Sense is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 28 Dec 2023 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 6.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 85%.[4] |
See also
Other Qlik Sense flaws
- CVE-2023-48365: HTTP tunneling ·
- CVE-2023-41265: HTTP tunneling ·
Other improper input validation flaws
- CVE-2026-93952, Arista VeloCloud Orchestrator: improper input validation ·
- CVE-2019-1068, Microsoft SQL Server: remote code execution ·
- CVE-2026-12569, PTC Windchill and FlexPLM: improper input validation ·
- CVE-2026-34910, Ubiquiti UniFi OS: improper input validation ·
- CVE-2026-6973, Ivanti Endpoint Manager Mobile (EPMM): improper input validation ·
Added the same day
- CVE-2023-41265, Qlik Sense: HTTP tunneling ·
Every Qlik flaw on CISA’s list · Everything added in December 2023
References
- ^ Cybersecurity and Infrastructure Security Agency. “Qlik Sense Path Traversal Vulnerability”. Known Exploited Vulnerabilities Catalog, added 7 Dec 2023.
- ^ National Institute of Standards and Technology. “CVE-2023-41266 Detail”. National Vulnerability Database, published 29 Aug 2023.
- ^ Qlik. Advisories and fixes: community.qlik.com, community.qlik.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.848, percentile 99.7, 31 Oct 2026.
- CVE Program. “CVE-2023-41266”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.