CVE
EspoCRM stored XSS in Knowledge Base article attachments
Affects EspoCRM before 9.3.11 and 10.x before 10.0.9, where a regular user with create or edit access to the Knowledge Base can attach a JavaScript file. Fixed in 9.3.11 and 10.0.9.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 10.0.9, 9.3.11
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affected EspoCRM versions: before 9.3.11 and 10.x before 10.0.9 Attacker needs create or edit access to the Knowledge Base scope An administrator must click the crafted link
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.37% · 30th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
EspoCRM before 9.3.11 and 10.x before 10.0.9 contains a stored cross-site scripting vulnerability in Knowledge Base articles that lets users with Knowledge Base create or edit access attach a JavaScript file and add a crafted link to the article body. When an administrator clicks the link, the script runs in their session and can create an administrator account with attacker-chosen credentials.
Who should check
Teams running EspoCRM 9.3.10 or earlier or 10.0.8 or earlier, especially those with Knowledge Base create or edit users and administrators who open article links.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.5/10CVSS 8.5
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Affected EspoCRM versions: before 9.3.11 and 10.x before 10.0.9 Attacker needs create or edit access to the Knowledge Base scope An administrator must click the crafted linkUpgrade to a fixed version: 10.0.9, 9.3.11.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-126305 (EspoCRM before 10.0.9 Stored XSS via Knowledge Base Article Attachments), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-126305 (entry last updated 2026-11-13):
Affected:
- espocrm espocrm: from 10.0.0, fixed in 10.0.9
- espocrm espocrm: fixed in 9.3.11
Fixed versions: 10.0.9, 9.3.11.
Conditions (all must be true for the bug to be hit):
- Affected EspoCRM versions: before 9.3.11 and 10.x before 10.0.9 (source: https://www.vulncheck.com/advisories/espocrm-before-10.0.9-stored-xss-via-knowledge-base-article-attachments)
- Attacker needs create or edit access to the Knowledge Base scope (source: https://github.com/espocrm/espocrm/security/advisories/GHSA-j6q5-9jwj-9p8q)
- An administrator must click the crafted link (source: https://github.com/espocrm/espocrm/security/advisories/GHSA-j6q5-9jwj-9p8q)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, low-privilege login, a user action.
CISA KEV: CVE-2026-126305 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126305 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/espocrm/espocrm/security/advisories/GHSA-j6q5-9jwj-9p8q
- https://www.vulncheck.com/advisories/espocrm-before-10.0.9-stored-xss-via-knowledge-base-article-attachments
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-126305
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-126305"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- espocrm espocrm
From 10.0.0 · fixed in 10.0.9
- espocrm espocrm
fixed in 9.3.11
Evidence 4
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-126305
Is CVE-2026-126305 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A regular user with create or edit access to the Knowledge Base scope can attach a JavaScript file to an article. When an administrator clicks a crafted link, EspoCRM runs the script in that administrator's session, and the script can create an administrator account with credentials chosen by the attacker.Source: vulncheck.com, github.com
Which versions are affected by CVE-2026-126305?
espocrm: from 10.0.0 before 10.0.9. espocrm: before 9.3.11.Source: cve.now feed data
Am I affected, and how do I check?
Affected versions are EspoCRM before 9.3.11 and 10.x before 10.0.9. The setup also requires a regular user with create or edit access to the Knowledge Base scope. Check the installed EspoCRM version and which roles have Knowledge Base create or edit access.Source: vulncheck.com, github.com
How do I fix CVE-2026-126305?
Upgrade to 9.3.11 on the 9.x line or to 10.0.9 on the 10.x line.Source: vulncheck.com, github.com