VulnerabilityPublished 21 Jul 2026

CVE-2026-55984: Gitea · Null Pointer Dereference in AddTime API Causes Authenticated Denial of Service

Affects code.gitea.io/giteaSource GCVE Database

Compare

Authoritative record:CVE-2026-55984· Low 2.7

Not known to be exploited · CVSS 2.7 Low : upgrade to 1.27.0 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

2.7Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.27.0

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 13 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by Gitea Limited
8 Jul 202609:19 UTC, 36 days before disclosure
CVE published
on cve.org
13 Aug 202616:44 UTC, t = 0
CISA SSVC assessment
proof of concept public
14 Aug 202617:39 UTC, 25 hours after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade code.gitea.io/gitea to 1.27.0.

Affected software

Product	Affected	Fixed in
Gocode.gitea.io/gitea	Affected <1.27.0	Fixed in 1.27.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### Summary The AddTime API handler continues execution after an error returned by `GetUserByName()`. When a repository administrator specifies a non-existent user name, an error response is generated but execution does not stop. Subsequent code dereferences a nil user pointer, resulting in a runtime panic. ### Details Affected endpoint: ```http POST /api/v1/repos/{owner}/{repo}/issues/{index}/times ``` Affected file: ```text routers/api/v1/repo/issue_tracked_time.go ``` Relevant code: ```go user, err = user_model.GetUserByName(ctx, form.User) if err != nil { ctx.APIErrorInternal(err) // missing return } ``` Execution continues to: ```go trackedTime, err := issues_model.AddTime( ctx, user, issue, form.Time, created, ) ``` When `GetUserByName()` fails, `user` is nil. The subsequent call dereferences the nil pointer and triggers a runtime panic. ### Proof of Concept Using a repository administrator account: ```http POST /api/v1/repos/owner/repo/issues/1/times Content-Type: application/json { "time": 3600, "user_name": "nonexistent_user_xyz" } ``` Result: ```text HTTP 500 runtime error: invalid memory address or nil pointer dereference ``` The stack trace indicates execution reaches the AddTime code path with a nil user object. ### Impact An authenticated repository administrator can repeatedly trigger server-side panics through the affected endpoint. Depending on deployment configuration and panic recovery behavior, this may result in request failures, stack trace disclosure, excessive log generation, or degraded service availability. ### Suggested Fix Add a return statement after the error response: ```go user, err = user_model.GetUserByName(ctx, form.User) if err != nil { ctx.APIErrorInternal(err) return } ```

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

Timeline

What to do

Affected software

Description

WeaknessesCWE-476

Technical details

References

Community reviews

Related threats