Cyber Resilience

CVE-2026-27169

XSS in Opensift ≤ 1.1.3

Published
21 February 2026
Modified
23 February 2026
Patch / advisory
CVSS Score v3.1 8.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L
EPSS Score 0.0035 28th percentile
Risk Priority 61 floored blend · peak EPSS

Summary

CVE-2026-27169 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Opensift Opensift. Its CVSS base score is 8.9 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 28th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as LLM Application Platforms; in the Other ATLAS/OWASP Terms risk domain.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-27169 is a cross-site scripting (XSS) vulnerability affecting OpenSift, an AI study tool that uses semantic search and generative AI to process large datasets. Versions 1.1.2-alpha and below render untrusted user or model-generated content in chat tool UI surfaces via unsafe HTML interpolation patterns. This improper encoding (CWE-116, CWE-79) allows stored content to execute arbitrary JavaScript when viewed in authenticated sessions. The vulnerability was published on 2026-02-21 and carries a CVSS v3.1 base score of 8.9 (AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L).

An attacker requires low privileges (PR:L) to influence stored study, quiz, or flashcard content, such as by injecting malicious payloads via user inputs or AI-generated outputs. Exploitation occurs over the network (AV:N) with low complexity when a victim with an authenticated session views the tainted content, requiring user interaction (UI:R). Successful attacks trigger JavaScript execution in the victim's browser with changed scope (S:C), enabling high-impact actions like data exfiltration (C:H), session manipulation (I:H), or limited disruption (A:L) as the victim within the local app session.

The issue is fixed in OpenSift version 1.1.3-alpha. Mitigation details are available in the GitHub release notes at https://github.com/OpenSift/OpenSift/releases/tag/v1.1.3-alpha and the security advisory at https://github.com/OpenSift/OpenSift/security/advisories/GHSA-qrpx-7cmv-5gv5, which practitioners should review for upgrade instructions and any interim workarounds.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

OpenSift is an AI study tool that sifts through large datasets using semantic search and generative AI. Versions 1.1.2-alpha and below render untrusted user/model content in chat tool UI surfaces using unsafe HTML interpolation patterns, leading to XSS. Stored content…

more

can execute JavaScript when later viewed in authenticated sessions. An attacker who can influence stored study/quiz/flashcard content could trigger script execution in a victim’s browser, potentially performing actions as that user in the local app session. This issue has been fixed in version 1.1.3-alpha.

CWE(s)

AI Security AnalysisAI

AI Category
LLM Application Platforms
Risk Domain
Other ATLAS/OWASP Terms
OWASP Top 10 for LLMs 2025
None mapped
AI-specific weaknesses CR
  • CWE-1426 — Generative model output reaches DOM sink without validation (XSS).
Mapped by Cyber Resilience · not in NVD. Poisoning and extraction cases are routed to MITRE ATLAS instead of a synthetic CWE.
Classification Reason
Matched keywords: ai, generative ai

Related Threats

MITRE ATT&CK Enterprise Techniques

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-32071Shared CWE-116, CWE-79
CVE-2023-39527Shared CWE-116, CWE-79
CVE-2023-37875Shared CWE-116, CWE-79
CVE-2023-2200Shared CWE-116, CWE-79
CVE-2023-1649Shared CWE-79
CVE-2023-3481Shared CWE-116, CWE-79
CVE-2023-28733Shared CWE-116, CWE-79
CVE-2023-25837Shared CWE-79
CVE-2023-22438Shared CWE-79
CVE-2023-27614Shared CWE-79

Affected Assets

opensift
opensift
≤ 1.1.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.2.1
  • V1.2.3
  • V1.3.2

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.

Input validation directly enforces neutralization of untrusted data before it reaches web output generation.

Output filtering can catch or sanitize unneutralized script content before it is served to users.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
prevents

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure coding standards explicitly require correct output encoding and escaping to preserve message structure.

finds

Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.

prevents

Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.

prevents

Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.

prevents

Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.

prevents

Application security requirements include explicit rules for safe output handling and encoding.

References