CVE-2026-56735

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (34th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 5.3Exploit: None knownExposed services: Not assessed

The CVE record names the fixed release — apply it.

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2 and 7.1.0, zammad's HTML sanitizer (HtmlSanitizer::Strict) blocks external URLs in to prevent remote content loading, but the srcset attribute, also allowlisted for , is not subject to the same check. This oversight allows an attacker to embed arbitrary external URLs in the srcset attribute just by sending an e-mail, effectively bypassing the external content protection. When an agent views the ticket containing the malicious srcset, the browser will silently load the attacker-controlled URL, resulting in the leakage of the agent's IP address, User-Agent, Referer, and the exact time the ticket was viewed. HtmlSanitizer::Strict got extended to block external URLs in the srcset attribute of tags. This was done to prevent tracking pixels and external content loading, which could compromise user privacy. This issue is fixed in versions 7.0.2 and 7.1.0.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: The CVE record names the fixed release. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
34th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

The CVE record names the fixed release. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 25, 2026

Last Modified

September 28, 2026

Advisory Details (2)

Auto-updated Sep 25, 2026
Fix named in the CVE record. Sources: github_commit, github.
github_commit

commit 02c1ff8dc659 (zammad/zammad)

Fix landed in zammad/zammad commit 02c1ff8dc659 — awaiting tagged release

https://github.com/zammad/zammad/commit/02c1ff8dc65961352dc047013bece9dff1f2ffb7
githubMentions a patch (unverified)

Improper neutralization of `srcset` attribute in IMG tags in Zammad · Advisory · zammad/zammad · GitHub

https://github.com/zammad/zammad/security/advisories/GHSA-7fwx-3xr4-qm6w

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 14× in last 7d / 33× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-09 04:29 UTCEG score recompute
  3. 2026-10-08 17:13 UTCEPSS rescore
  4. 2026-10-08 05:27 UTCEG score recompute
  5. 2026-10-07 23:48 UTCEPSS rescore
  6. 2026-10-07 06:24 UTCEG score recompute
  7. 2026-10-06 15:18 UTCEPSS rescore
  8. 2026-10-06 07:19 UTCEG score recompute
  9. 2026-10-05 17:43 UTCEPSS rescore
  10. 2026-10-05 08:16 UTCEG score recompute
  11. 2026-10-04 23:22 UTCEPSS rescore
  12. 2026-10-04 09:14 UTCEG score recompute
  13. 2026-10-03 14:26 UTCEPSS rescore
  14. 2026-10-03 10:11 UTCEG score recompute
  15. 2026-10-02 17:56 UTCEPSS rescore
  16. 2026-10-02 11:08 UTCEG score recompute
  17. 2026-10-01 19:50 UTCEPSS rescore
  18. 2026-10-01 12:05 UTCEG score recompute
  19. 2026-09-30 15:03 UTCEPSS rescore
  20. 2026-09-30 13:03 UTCEG score recompute
  21. 2026-09-29 15:22 UTCEPSS rescore
  22. 2026-09-29 13:53 UTCEG score recompute
  23. 2026-09-28 14:51 UTCEG score recompute
  24. 2026-09-28 13:51 UTCEPSS rescore
  25. 2026-09-27 17:40 UTCEG score recompute
Show 8 more
  1. 2026-09-27 13:48 UTCEPSS rescore
  2. 2026-09-26 18:37 UTCEG score recompute
  3. 2026-09-26 15:59 UTCEPSS rescore
  4. 2026-09-25 19:34 UTCEG score recompute
  5. 2026-09-25 19:11 UTCEG score recompute
  6. 2026-09-25 18:38 UTCEG score recompute
  7. 2026-09-25 17:19 UTCEG score recompute
  8. 2026-09-25 17:19 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-56735?
CVE-2026-56735 is a medium vulnerability published on September 25, 2026. Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2 and 7.1.0, zammad's HTML sanitizer (HtmlSanitizer::Strict) blocks external URLs in to prevent remote content loading, but the srcset attribute, also allowlisted for , is not subject to the same check. This oversight…
When was CVE-2026-56735 disclosed?
CVE-2026-56735 was first published on September 25, 2026, with the most recent update on September 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56735 actively exploited?
CVE-2026-56735 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-56735?
CVE-2026-56735 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-56735?
The CVE record for CVE-2026-56735 names the fix: "This issue is fixed in versions 7.0.2 and 7.1.0."

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-56735

Explore →

Is Your Infrastructure Affected by CVE-2026-56735?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs