Bytebase before 3.16.0 contains an authorization bypass vulnerability in the UpdateIssueComment handler that allows low-privileged project users to modify comments in other projects by supplying a foreign comment UID. Attackers with any project role, including Project Viewer, can set their own project's issue as parent and reference another project's comment UID to overwrite comments they cannot access.
CVE-2026-115321
MEDIUMPre-NVD 4.34.3Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
“—” beside the score: it is equal to the CVSS score beside it.
Score 4.3 from GitHub Security Advisory published 2026-10-22. A secondary CVSS source baseline 4.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Also known asEUVD-2026-108123 (ENISA EUVD) · GHSA-27j2-crf8-3w95 (GitHub Security Advisories)Source: ENISA EUVD
4.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 4.3Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 4.3
- EG Score
- 4.3MEDIUMhigh confidence
- EG Risk
- 19EG Risk 19/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity43% × 45%Impact severity (EG Severity): CVSS 4.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.2% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.3%
- EPSS %ILE
- 20th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (4.3): severity, escalated by confirmed exploitation. This CVE's 4.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 4.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
October 22, 2026
Last Modified
October 23, 2026
Advisory Details (7)
Auto-updated Oct 22, 2026Patch available. Sources: github_commit, github_pr, github_release.
Web page
Bytebase before 3.16.0 Authorization Bypass via UpdateIssueComment | Advisories | VulnCheck
https://www.vulncheck.com/advisories/bytebase-before-3.16.0-authorization-bypass-via-updateissuecommentGitHub release Patch Available
Release 3.16.0
Patch available: bytebase/bytebase 3.16.0
https://github.com/bytebase/bytebase/releases/tag/3.16.0GitHub pull request Patch Available
fix: validate issue ownership in UpdateIssueComment to prevent IDOR
Patch available: bytebase/bytebase 3.16.0 (PR #19552 merged 2026-03-09)
https://github.com/bytebase/bytebase/pull/19552Web page
Security: Cross-project IDOR in UpdateIssueComment and rollout service endpoints · Issue #19369 · bytebase/bytebase · GitHub
https://github.com/bytebase/bytebase/issues/19369GitHub commit Patch Available
commit 270e25529731 (bytebase/bytebase)
Patch available: bytebase/bytebase 3.16.0 (contains commit 270e25529731)
https://github.com/bytebase/bytebase/commit/270e25529731b59988b58f4a4b3bda431c748bc9Web page
bytebase/backend/api/v1/issue_service.go at 3.15.1 · bytebase/bytebase · GitHub
https://github.com/bytebase/bytebase/blob/3.15.1/backend/api/v1/issue_service.go#L1116Web page
GitHub - bytebase/bytebase: Database governance built for humans and agents — controlling changes and access across every major database. · GitHub
https://github.com/bytebase/bytebaseVendor Advisories for CVE-2026-115321(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 13× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-25 14:50 UTCEG score recompute
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.2% · 12th percentile
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.2% · 12th percentile
- 2026-10-23 15:18 UTCEG score recompute
- 2026-10-23 15:18 UTCGHSA enrichmentGHSA-27j2-crf8-3w95 · GitHub CVSS 4.3
- 2026-10-22 17:50 UTCEG score recompute
- 2026-10-22 17:50 UTCGHSA enrichmentGHSA-27j2-crf8-3w95 · GitHub CVSS 4.3
- 2026-10-22 11:26 UTCEG score recompute
- 2026-10-22 11:01 UTCEG score recomputeFirst assessed: 4.3 MEDIUM
- 2026-10-22 11:00 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-115321?
CVE-2026-115321 is a medium-severity vulnerability; its CVE record was published on October 22, 2026. Bytebase before 3.16.0 contains an authorization bypass vulnerability in the UpdateIssueComment handler that allows low-privileged project users to modify comments in other projects by supplying a foreign comment UID. Attackers with any project role, including Project Viewer, can set their own…
When was CVE-2026-115321 made public?
CVE-2026-115321 was made public on March 9, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on October 22, 2026. EchelonGraph's copy of the record carries a last-modified date of October 23, 2026; the record at its source may have been updated since.
Is CVE-2026-115321 actively exploited?
CVE-2026-115321 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (20th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-115321?
CVE-2026-115321 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-115321?
A fix for CVE-2026-115321 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-115321 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-115321
Is Your Infrastructure Affected by CVE-2026-115321?
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